[Desktop/Windows] Sidebar icons overlayed when viewing YouTube/Vimeo fullscreen

[4rnv]

Description

Sidebar icons are overlayed on top while watching videos in fullscreen. Tested it on vimeo and youtube, and the problem occurs on both.

OS: Windows 10 Home 22H2 19045.4123 Brave Version: v1.63.174 Chromium Version: 122.0.6261.128 (Official Build) (64-bit)

I have also been able to replicate the issue in guest mode and private windows. Changing the sidebar from 'always' to 'on mouseover' doesn't help, since on hovering over the left edge in fullscreen the icons still appear.

Steps to Reproduce

1. Open any video on youtube.com or vimeo.com
2. Open video in fullscreen
3. The sidebar icons, which until recently were being hidden, are still visible on top of the video, although clicking them does nothing.

Actual result:

https://github.com/brave/brave-browser/assets/146211212/6393df53-84ae-47d5-95bd-f513a01f7d7b

^ Screenrecord of issue as visible on Youtube

^ Vimeo screenshot

Expected result:

Reproduces how often:

Easily reproduced. Also occurs in private windows and guest mode.

In guest mode the other icons aren't visible since it's guest mode, but the bookmarks and wallet icons still are (see top left of below screenshot).

Brave version (brave://version info)

Brave | 1.63.174 Chromium: 122.0.6261.128 (Official Build) (64-bit) Revision | 0d369d4e1dfee7bcea82774079dc8cd658746c98 OS | Windows 10 Version 22H2 (Build 19045.4123)

Version/Channel Information:

• Can you reproduce this issue with the current release? I am using the latest stable version.
• Can you reproduce this issue with the beta channel? Currently I cannot test it on the beta channel.
• Can you reproduce this issue with the nightly channel? Currently I cannot test it on the nightly channel.

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? No.
• Does the issue resolve itself when disabling Brave Rewards? No.
• Is the issue reproducible on the latest version of Chrome? Chrome has a side 'panel' rather than a sidebar, the implementation on chrome takes more screen space and reduces the viewport of the video in fullscreen, but doesn't overlay on top of the video.

Miscellaneous Information:

I use uBlock Origin, but since the issue is also replicated in guest mode (where all extensions are disabled), I don't think uBO would affect this issue in any form.

[4rnv]

I see that this issue is a duplicate of https://github.com/brave/brave-browser/issues/35811 and has been fixed in the nightly version https://github.com/brave/brave-core/pull/22414, but not yet on stable. I will be closing it for now.