I found this problem referenced here:
I seem to be having this exact problem. I can reproduce it by launching Brave while the Accessibility Keyboard is running, then clicking on the menu/hamburger button in the toolbar.
If I don’t have Accessibility Keyboard running, Brave seems to work as expected.
I’m not having the same problem in Chrome.
[Version 1.11.97 Chromium: 84.0.4147.89 (Official Build) (64-bit)](https://brave.com/latest/)