Error on Anki 2.1.63

This error happened while changing overview/review screens very fast using shortcuts. I often do this, but this is the first time I see this error.

Anki 2.1.63 (f356f177) Python 3.9.15 Qt 6.5.0 PyQt 6.5.0
Platform: Linux-6.3.2-arch1-1-x86_64-with-glibc2.37
Flags: frz=True ao=True sv=2
Add-ons, last update check: 2023-05-24 09:52:18

Caught exception:
Traceback (most recent call last):
  File "aqt.toolbar", line 216, in <lambda>
TypeError: setFixedHeight(self, h: int): argument 1 has unexpected type 'NoneType'

@kleinerpirat any ideas?