can't go fullscreen with picture-in-picture mode (firefox)

cvcarloscv · 2026-08-30 14:17:46

i'm using arch linux with xfce (x11 with default compositor and WM.) system is updated to this date.

firefox works and i can go fullscreen when using the browser normally. i can't go fullscreen in PiP mode though: the pop-up video player's HUD freezes when i click the fullscreen icon or press F. no fullscreen, video keeps playing though. also i can use the HUD for pausing, volume, etc, its just stuck. closing PiP and starting it again fixes the HUD.

i have no idea how to debug this, and i really want the fullscreen option to work. it used to work on debian 13 before, but not on arch. what do i do?

video showcasing the problem

CPU: AMD Ryzen 5 3500C (8) @ 2.10

GPU: AMD Radeon Vega 8 Graphics [Integrated]

seth · 2026-08-30 15:26:43

Sure you're not trying to use https://wiki.archlinux.org/title/Xfce#U … nd_support ?
Does it work as expected in an openbox session?

cvcarloscv · 2026-08-30 18:42:53

seth wrote:

Sure you're not trying to use https://wiki.archlinux.org/title/Xfce#U … nd_support ?

nope! 100% sure i'm using x11. here's the full output from fastfetch:

                  -`                     cv@arch-ezkinil
                 .o+`                    ---------------
                `ooo/                    OS: Arch Linux x86_64
               `+oooo:                   Host: Ezkinil (rev4)
              `+oooooo:                  Kernel: Linux 7.1.11-zen1-1-zen
              -+oooooo+:                 Uptime: 7 hours, 8 mins
            `/:-:++oooo+:                Packages: 1401 (pacman)
           `/++++/+++++++:               Shell: zsh 5.9.2
          `/++++++++++++++:              Display (AUO403D): 1920x1080 in 14", 60 Hz
         `/+++ooooooooooooo/`            DE: Xfce4 4.20
        ./ooosssso++osssssso+`           WM: Xfwm4 (X11)
       .oossssso-````/ossssss+`          WM Theme: Redmond97 SE Jet Purple
      -osssssso.      :ssssssso.         Theme: Redmond97 SE Jet Purple [GTK2/3/4]
     :osssssss/        osssso+++.        Icons: SE98 [GTK2/3/4]
    /ossssssss/        +ssssooo/-        Font: Tahoma (10pt) [GTK2/3/4]
  `/ossssso+/:-        -:/+osssso+-      Cursor: Chicago95_Standard_Cursors_Black (16px)
 `+sso+:-`                 `.-/+oso:     Terminal: xfce4-terminal 1.2.0
`++:.                           `-/+/    Terminal Font: Less Perfect DOS VGA (12pt)
.`                                 `/    CPU: AMD Ryzen 5 3500C (8) @ 2.10 GHz
                                         GPU: AMD Radeon Vega 8 Graphics [Integrated]
                                         Memory: 3.10 GiB / 7.21 GiB (43%)
                                         Swap: 1.43 GiB / 12.00 GiB (12%)
                                         Disk (/): 200.19 GiB / 462.65 GiB (43%) - btrfs
                                         Battery (AP19B8M): 99% [AC Connected]
                                         Locale: C.UTF-8

seth wrote:

Does it work as expected in an openbox session?

it doesn't work! same thing in the video happens. weirdly enough, i tried in iceWM just to test a different enviroment and PiP does work in there. what could be happening?

seth · 2026-08-30 19:59:49

I don't think IceWM is NETWM compatible - what's the output of "xprop" for both windows (browser an video) when this happens?
(The cursor will turn into a "+", you can click a window and it will print a lot of text on the console)

What WM did you use on Debian?
XFWM4 as well?

cvcarloscv · Yesterday 21:33:45

seth wrote:

what's the output of "xprop" for both windows (browser an video) when this happens?

xprop output on pastebin. i did the command after PiP fullscreen button was clicked and UI got frozen. (done on xfwm4, did you mean i should do it on icewm?)

seth wrote:

What WM did you use on Debian?

KDE default (kwin), also on x11

killertofus · Yesterday 23:27:46

does wayland work?

seth · Today 05:43:58

WM_STATE(WM_STATE):
		window state: Normal
_NET_WM_STATE(ATOM) = _NET_WM_STATE_SKIP_PAGER, _NET_WM_STATE_SKIP_TASKBAR, _NET_WM_STATE_ABOVE
		Initial state is Normal State.

None of those windows is set to fullscreen (the above one is the PiP one)

_NET_FRAME_EXTENTS(CARDINAL) = 0, 0, 0, 0

Does it work if you run

killall firefox; MOZ_GTK_TITLEBAR_DECORATION=system firefox

Arch Linux

#1 2026-08-30 14:17:46

can't go fullscreen with picture-in-picture mode (firefox)

#2 2026-08-30 15:26:43

Re: can't go fullscreen with picture-in-picture mode (firefox)

#3 2026-08-30 18:42:53

Re: can't go fullscreen with picture-in-picture mode (firefox)

#4 2026-08-30 19:59:49

Re: can't go fullscreen with picture-in-picture mode (firefox)

#5 Yesterday 21:33:45

Re: can't go fullscreen with picture-in-picture mode (firefox)

#6 Yesterday 23:27:46

Re: can't go fullscreen with picture-in-picture mode (firefox)

#7 Today 05:43:58

Re: can't go fullscreen with picture-in-picture mode (firefox)

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