Bug: Fullscreen behavior broken with YouTube on Brave

[muskats]

Describe the bug

When attempting to enter fullscreen on a YouTube video in Brave, the browser enters a full-window/fullscreen-page (i.e. pressing F11) instead of putting only the video into fullscreen. Once, in fullscreen-page it is possible to enter and exit fullscreen video view normally (via the dedicated button or by pressing the F key).
The video remains at its normal size within the webpage. Playback is not interrupted, and the transition is smooth both into and out from the fullscreen.

This only happens when Brave is maximized.

To Reproduce

Steps to reproduce the behavior:

1. Open Brave
2. Maximize the window using Super+M or COSMIC tiling
3. Navigate to YouTube and play any video
4. Click the YouTube fullscreen button or press F

Expected behavior

The YouTube video should enter video fullscreen mode directly, without forcing the entire browser [page] into "F11 fullscreen".

System Info:

• Pop!_OS 24.04 LTS (COSMIC)
• Wayland session (cosmic-comp)
• GPU:
  • GPU: AMD ATI 05:00.0 Phoenix1
  • GPU: NVIDIA GeForce RTX 4070 Max-Q / Mobile
• COSMIC packages:

cosmic-comp: 0.1~1762354162~24.04~e55d16b
cosmic-session: 0.1.0~1761786717~24.04~472db42
cosmic-settings: 0.1.0~1762446699~24.04~e2bb9ad
cosmic-randr: 0.1.0~1757248943~24.04~bce9cdf

• Browser:
  • Brave v1.84.135 (Nov 6, 2025)
  • Chromium 142.0.7444.135

[Zeanix]

I have experienced this as well on both pop 24.04 and fedora. For me it happens with both Vivaldi and Brave.

[devimalka]

can confirm this. it's not also applied to the YouTube mostly any video that i'm trying to play on cosmic-DE, the full screen options goes to the browser full screen mode and the ESC key to return back to normal doesn't work. have to right click and select the Exit full-screen

[muskats]

can confirm this. it's not also applied to the YouTube mostly any video that i'm trying to play on cosmic-DE, the full screen options goes to the browser full screen mode and the ESC key to return back to normal doesn't work. have to right click and select the Exit full-screen

This seems to be the case. I was able to reproduce the exact issue in the Jellyfin webplayer.

[Zeanix]

It seems to be fixed for me in Vivaldi on the lastest release of Cosmic, the issue is still there in brave however.

[Milli189]

I still have this issue

[muskats]

It seems to be fixed for me in Vivaldi on the lastest release of Cosmic, the issue is still there in brave however.

Unfortunately, I still have the issue.

---

System Info - Updated:

COSMIC packages:

cosmic-comp: 0.1~1765324739~24.04~fa88002
cosmic-session: 0.1.0~1765297260~24.04~f409307
cosmic-settings: 0.1.0~1765390658~24.04~7965d39
cosmic-randr: 0.1.0~1765297242~24.04~f5923d1

Browser:

• Brave v1.85.116 (Dec 11, 2025)
• Chromium 143.0.7499.110

[fodevac33]

Same issue over here on Brave. Pop Os 24.

[jjmacid]

Hi I also have the same problem and it still persists even with today's Brave update to 1.85.117 (Chromium 143.0.7499.146). It doesn't happen in Firefox.

[Zergvp]

It is reported here also. It happens on Windows, Fedora other distros, not only in Cosmic. It seems that it is a Brave specific problem.

https://community.brave.app/t/fullscreen-browser-bug/647112

[Milli189]

It is reported here also. It happens on Windows, Fedora other distros, not only in Cosmic. It seems that it is a Brave specific problem.

https://community.brave.app/t/fullscreen-browser-bug/647112

I've never had this issue in fedora kde or gnome, only in cosmic

[Zeanix]

It is reported here also. It happens on Windows, Fedora other distros, not only in Cosmic. It seems that it is a Brave specific problem.

https://community.brave.app/t/fullscreen-browser-bug/647112

I doubt it happens anywhere else. I have never seen it on either Gnome, KDE, Mate, XFCE or Windows. It's also just one guy reporting it, with no one being able to reproduce it.

I still believe it's an issue specific to cosmic, as other browsers had the same behavior.

[Zergvp]

I still believe it's an issue specific to cosmic, as other browsers had the same behavior.

No, it doesn't happen in Firefox on Pop_OS! COSMIC. Can't confirm other browsers since I don't use any other but I can install any other if someone wants me to check. So it is either Brave or Brave on Pop!OS. Although it happens also to a user on Windows.

[Zergvp]

Since I remembered that Firefox doesn’t use Chromium, I installed Chromium and surprise, the PROBLEM ALSO HAPPENS there.

[Milli189]

Since I remembered that Firefox doesn’t use Chromium, I installed Chromium and surprise, the PROBLEM ALSO HAPPENS there.

as you can see it's an issue specific to Cosmic with how it handles chromium based browsers