Visual artifact: Sidebar shadow remains visible after closing sidebar

Description of the issue: Sidebar shadow/overlay persists after sidebar is collapsed or closed. A visual artifact remains visible on the left portion of the screen where the sidebar was previously displayed, overlaying the main content area.

Steps to Reproduce:

  1. Open Brave browser with sidebar visible

  2. Collapse or close the sidebar (toggle sidebar off)

  3. Observe the main content area where sidebar was previously located

Actual Result: A shadow or overlay element remains visible on the left side of the screen after the sidebar is hidden. The artifact persists and obscures part of the main window content.

Expected result: When the sidebar is collapsed or closed, all associated visual elements (including shadows, overlays, and backdrop elements) should be completely removed from view. The main content area should be fully visible without any residual shadow artifacts.

Reproduces how often: Intermittent - occurs sometimes when toggling the sidebar closed. Disappears when a new tab is opened with CRTL+T

Operating System and Brave Version:

  • OS: Windows 11

  • Brave Version: 1.82.172 (Official Build) (64-bit)

  • Chromium Version: 140.0.7339.207

Additional Information: The issue appears to be a rendering bug where shadow/overlay DOM elements or CSS pseudo-elements associated with the sidebar are not being properly cleaned up during the sidebar’s state transition. Possible z-index stacking context issue or incomplete CSS transition leaving opacity/transform values in intermediate state.

I know you said the issue is intermittent but how often would you say it occurs? I cannot get this to reproduce on my end – tested on Win 11 and macOS systems. Also curious if you have any extensions installed at this time and if disabling has any effect on the issue.

Additionally, if you instead use the sidebar button on the browser toolbar to toggle the sidebar open/closed, do you get the artifact this way as well?

It just happens really randomly it seems. Next time it happens I will try to recall what led up to it.

got same issue and got repro steps on my end!

i have few tabs pinned
i have typically 1 or two tabs non pined

when i close last unpinned tab and only those 1-2 pinned left
there is a shadov of sidebar visible untill i open new - non pinned tab

W11 Home - 10.0.26200 Build 26200
Brave 1.84.141 (Official Build) (64-bit)
Chromium: 142.0.7444.176

I can send vids, pics
My brave settings is:
media mute on speaker click: off
tabs on side with autohide