White border/glitch on the left side of the screen on macOS

[brunnopleffken]

Description

In Brave Nightly on macOS (w/ Apple Silicon M1 Pro), when the browser window color is light (regardless of the theme used on macOS), a white border persists on the left side of the screen. This doesn't happen on the right side.

From what I can tell, the white border belongs to the browser window itself, as home screen items and website content are shifted 1 pixel to the right when switching windows between Brave Nightly and Brave Stable.

Steps to Reproduce

1. Use a dark wallpaper on the New Tab screen; or access a dark-themed website.
2. This happens in macOS light and dark themes as long as the color of the browser itself is light.

Actual result:

A white border persists only on the left side of the screen (this doesn't happen with other Chromium browsers such as Vivaldi and Opera).

On the right side of the screen, everything is normal.

Expected result:

The light border shouldn't exist.

Reproduces how often:

Always.

Brave version (brave://version info)

Brave | 1.51.38 Chromium: 111.0.5563.64 (Official Build) nightly (arm64)
Revision | c710e93d5b63b7095afe8c2c17df34408078439d-refs/branch-heads/5563@{#995}
OS | macOS Version 13.2.1 (Build 22D68)

Version/Channel Information:

• Can you reproduce this issue with the current release? Everything's fine with Brave 1.49.120
• Can you reproduce this issue with the beta channel? Everything's also fine with Brave 1.50.93
• Can you reproduce this issue with the nightly channel? Yes, I use the Nightly channel.

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? No, it doesn't, as it's a browser window glitch.
• Does the issue resolve itself when disabling Brave Rewards? I don't use Brave Rewards.
• Is the issue reproducible on the latest version of Chrome? No.

[simonhong]

It seems this comes from vertical tab feature.
If you disable Vertical tabs from brave://flags, that line will be gone.

[brunnopleffken]

Confirmed. It's gone if #brave-vertical-tabs is disabled.