New system install from scratch, cwm window manager, added extension uBlock Origin to chromium and no other settings. IF you click on the tab bar of the chromium window to maximize, a nice animation will start with the window going repeatedly between maximum size and original size. It can be reproduced numerous times.
One I use GTK+ and Use system title bars and borders options, this behaviour is not present. Even if i go back to disable them, the flickering cannot be reproduced. OpenBSD 6.8-current (GENERIC.MP) #142: Tue Oct 27 15:23:47 MDT 2020 chromium-86.0.4240.111p0 cwm as window manager
