6.3.5-6050 doesn't start

I got my zoom from https://zoom.us/client/6.3.5.6065/zoom_x86_64.pkg.tar.xz on NixOS (x86_64 linux).

After installation it idles at 100% CPU for a while, without starting the GUI, then crashes. I cannot downgrade to the last working version, which was 6.2.11-5069 , because that no longer allows SSO-login (see picture).

Many NixOS users have the same experience. What do we do?