I am having the same problem, of my carefully trying to drop the Brave icon on the suggested target, refusing to be recognized, or even responded to at all. I have tried zooming in and out in addition to the default zoom. But nope.
Majaro Linux 21.2. KDE Plasma 5.23.4
Version 1.32.115 Chromium: 96.0.4664.93 (Official Build) unknown (64-bit)