Try disabling the IPv6 settings. Go to Edit Connections, select the connection you want to edit, select the IPv6 Settings tab, select Ignore from the Method drop-down menu.
Whoops, I forgot I still had this open. I wasn't able to actually fix the issue, so I just disabled the IPv6 tunnel on my router.
]]>journalctl -b --no-pager | grep NetworkManager
Jul 20 00:44:05 desktop NetworkManager[390]: <info> NetworkManager (version 0.9.8.10) is starting...
Jul 20 00:44:05 desktop NetworkManager[390]: <info> Read config file /etc/NetworkManager/NetworkManager.conf
Jul 20 00:44:05 desktop NetworkManager[390]: <info> WEXT support is enabled
Jul 20 00:44:06 desktop NetworkManager[390]: <info> Loaded plugin keyfile: (c) 2007 - 2010 Red Hat, Inc. To report bugs please use the NetworkManager mailing list.
Jul 20 00:44:06 desktop NetworkManager[390]: keyfile: parsing Profile 1 ...
Jul 20 00:44:06 desktop NetworkManager[390]: keyfile: read connection 'Profile 1'
Jul 20 00:44:06 desktop NetworkManager[390]: <info> monitoring kernel firmware directory '/lib/firmware'.
Jul 20 00:44:06 desktop NetworkManager[390]: <info> WiFi enabled by radio killswitch; enabled by state file
Jul 20 00:44:06 desktop NetworkManager[390]: <info> WWAN enabled by radio killswitch; enabled by state file
Jul 20 00:44:06 desktop NetworkManager[390]: <info> WiMAX enabled by radio killswitch; enabled by state file
Jul 20 00:44:06 desktop NetworkManager[390]: <info> Networking is enabled by state file
Jul 20 00:44:06 desktop NetworkManager[390]: <warn> failed to allocate link cache: (-26) Protocol mismatch
Jul 20 00:44:06 desktop NetworkManager[390]: <info> (enp4s0): carrier is OFF
Jul 20 00:44:06 desktop NetworkManager[390]: <info> (enp4s0): new Ethernet device (driver: 'tg3' ifindex: 2)
Jul 20 00:44:06 desktop NetworkManager[390]: <info> (enp4s0): exported as /org/freedesktop/NetworkManager/Devices/0
Jul 20 00:44:06 desktop NetworkManager[390]: <info> (enp4s0): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2]
Jul 20 00:44:06 desktop NetworkManager[390]: <info> (enp4s0): preparing device.
Jul 20 00:44:06 desktop NetworkManager[390]: <info> (enp4s0): deactivating device (reason 'managed') [2]
Jul 20 00:44:06 desktop NetworkManager[390]: <warn> /sys/devices/virtual/net/lo: couldn't determine device driver; ignoring...
Jul 20 00:44:06 desktop NetworkManager[390]: <warn> /sys/devices/virtual/net/lo: couldn't determine device driver; ignoring...
Jul 20 00:44:06 desktop NetworkManager[390]: <warn> Couldn't acquire object manager proxy: Error calling StartServiceByName for org.bluez: GDBus.Error:org.freedesktop.systemd1.LoadFailed: Unit dbus-org.bluez.service failed to load: No such file or directory.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> (enp4s0): carrier now ON (device state 20)
Jul 20 00:44:09 desktop NetworkManager[390]: <info> (enp4s0): device state change: unavailable -> disconnected (reason 'carrier-changed') [20 30 40]
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Auto-activating connection 'Profile 1'.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) starting connection 'Profile 1'
Jul 20 00:44:09 desktop NetworkManager[390]: <info> (enp4s0): device state change: disconnected -> prepare (reason 'none') [30 40 0]
Jul 20 00:44:09 desktop NetworkManager[390]: <info> NetworkManager state is now CONNECTING
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 1 of 5 (Device Prepare) scheduled...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 1 of 5 (Device Prepare) started...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 2 of 5 (Device Configure) scheduled...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 1 of 5 (Device Prepare) complete.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 2 of 5 (Device Configure) starting...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> (enp4s0): device state change: prepare -> config (reason 'none') [40 50 0]
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 2 of 5 (Device Configure) successful.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 3 of 5 (IP Configure Start) scheduled.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 2 of 5 (Device Configure) complete.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 3 of 5 (IP Configure Start) started...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> (enp4s0): device state change: config -> ip-config (reason 'none') [50 70 0]
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Beginning DHCPv4 transaction (timeout in 45 seconds)
Jul 20 00:44:09 desktop NetworkManager[390]: <info> dhcpcd started with pid 1559
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Beginning IP6 addrconf.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 3 of 5 (IP Configure Start) complete.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> (enp4s0): DHCPv4 client pid 1559 exited with status 0
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 4 of 5 (IPv4 Configure Timeout) scheduled...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 4 of 5 (IPv4 Configure Timeout) started...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 4 of 5 (IPv4 Configure Timeout) complete.
Jul 20 00:44:11 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 3 of 5 (IP Configure Start) starting DHCPv6 as requested by IPv6 router...
Jul 20 00:44:11 desktop NetworkManager[390]: <info> Activation (enp4s0) Beginning DHCPv6 transaction (timeout in 45 seconds)
Jul 20 00:44:11 desktop NetworkManager[390]: <warn> the dhcpcd backend does not support IPv6.
Jul 20 00:48:35 desktop NetworkManager[390]: <warn> error monitoring device for netlink events: No buffer space available
desktop :: ~ % journalctl -b --no-pager | grep NetworkManager
Jul 20 00:44:05 desktop NetworkManager[390]: <info> NetworkManager (version 0.9.8.10) is starting...
Jul 20 00:44:05 desktop NetworkManager[390]: <info> Read config file /etc/NetworkManager/NetworkManager.conf
Jul 20 00:44:05 desktop NetworkManager[390]: <info> WEXT support is enabled
Jul 20 00:44:06 desktop NetworkManager[390]: <info> Loaded plugin keyfile: (c) 2007 - 2010 Red Hat, Inc. To report bugs please use the NetworkManager mailing list.
Jul 20 00:44:06 desktop NetworkManager[390]: keyfile: parsing Profile 1 ...
Jul 20 00:44:06 desktop NetworkManager[390]: keyfile: read connection 'Profile 1'
Jul 20 00:44:06 desktop NetworkManager[390]: <info> monitoring kernel firmware directory '/lib/firmware'.
Jul 20 00:44:06 desktop NetworkManager[390]: <info> WiFi enabled by radio killswitch; enabled by state file
Jul 20 00:44:06 desktop NetworkManager[390]: <info> WWAN enabled by radio killswitch; enabled by state file
Jul 20 00:44:06 desktop NetworkManager[390]: <info> WiMAX enabled by radio killswitch; enabled by state file
Jul 20 00:44:06 desktop NetworkManager[390]: <info> Networking is enabled by state file
Jul 20 00:44:06 desktop NetworkManager[390]: <warn> failed to allocate link cache: (-26) Protocol mismatch
Jul 20 00:44:06 desktop NetworkManager[390]: <info> (enp4s0): carrier is OFF
Jul 20 00:44:06 desktop NetworkManager[390]: <info> (enp4s0): new Ethernet device (driver: 'tg3' ifindex: 2)
Jul 20 00:44:06 desktop NetworkManager[390]: <info> (enp4s0): exported as /org/freedesktop/NetworkManager/Devices/0
Jul 20 00:44:06 desktop NetworkManager[390]: <info> (enp4s0): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2]
Jul 20 00:44:06 desktop NetworkManager[390]: <info> (enp4s0): preparing device.
Jul 20 00:44:06 desktop NetworkManager[390]: <info> (enp4s0): deactivating device (reason 'managed') [2]
Jul 20 00:44:06 desktop NetworkManager[390]: <warn> /sys/devices/virtual/net/lo: couldn't determine device driver; ignoring...
Jul 20 00:44:06 desktop NetworkManager[390]: <warn> /sys/devices/virtual/net/lo: couldn't determine device driver; ignoring...
Jul 20 00:44:06 desktop NetworkManager[390]: <warn> Couldn't acquire object manager proxy: Error calling StartServiceByName for org.bluez: GDBus.Error:org.freedesktop.systemd1.LoadFailed: Unit dbus-org.bluez.service failed to load: No such file or directory.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> (enp4s0): carrier now ON (device state 20)
Jul 20 00:44:09 desktop NetworkManager[390]: <info> (enp4s0): device state change: unavailable -> disconnected (reason 'carrier-changed') [20 30 40]
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Auto-activating connection 'Profile 1'.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) starting connection 'Profile 1'
Jul 20 00:44:09 desktop NetworkManager[390]: <info> (enp4s0): device state change: disconnected -> prepare (reason 'none') [30 40 0]
Jul 20 00:44:09 desktop NetworkManager[390]: <info> NetworkManager state is now CONNECTING
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 1 of 5 (Device Prepare) scheduled...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 1 of 5 (Device Prepare) started...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 2 of 5 (Device Configure) scheduled...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 1 of 5 (Device Prepare) complete.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 2 of 5 (Device Configure) starting...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> (enp4s0): device state change: prepare -> config (reason 'none') [40 50 0]
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 2 of 5 (Device Configure) successful.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 3 of 5 (IP Configure Start) scheduled.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 2 of 5 (Device Configure) complete.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 3 of 5 (IP Configure Start) started...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> (enp4s0): device state change: config -> ip-config (reason 'none') [50 70 0]
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Beginning DHCPv4 transaction (timeout in 45 seconds)
Jul 20 00:44:09 desktop NetworkManager[390]: <info> dhcpcd started with pid 1559
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Beginning IP6 addrconf.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 3 of 5 (IP Configure Start) complete.
Jul 20 00:44:09 desktop NetworkManager[390]: <info> (enp4s0): DHCPv4 client pid 1559 exited with status 0
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 4 of 5 (IPv4 Configure Timeout) scheduled...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 4 of 5 (IPv4 Configure Timeout) started...
Jul 20 00:44:09 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 4 of 5 (IPv4 Configure Timeout) complete.
Jul 20 00:44:11 desktop NetworkManager[390]: <info> Activation (enp4s0) Stage 3 of 5 (IP Configure Start) starting DHCPv6 as requested by IPv6 router...
Jul 20 00:44:11 desktop NetworkManager[390]: <info> Activation (enp4s0) Beginning DHCPv6 transaction (timeout in 45 seconds)
Jul 20 00:44:11 desktop NetworkManager[390]: <warn> the dhcpcd backend does not support IPv6.
Jul 20 00:48:35 desktop NetworkManager[390]: <warn> error monitoring device for netlink events: No buffer space available