beta 8.2.0: resizing browser window causes flashing borders

Summary:
When resizing the browser window, it shows flashing black and white right and bottom borders.
Looks like the contents of the window can't keep up with the new window size.

Steps to Reproduce:
Resize the browser windows by dragging one of its corners or edges.

Expected Results:
No flashing borders

Actual Results:
Flashing borders. White when you enlarge the screen, black when you reduce the size.

Regression:
Always happens.

Does not happen when patcher windows are resized.

Notes:
See video, showing resizing of patcher window first, then the browser.