It is a known problem if you have undocked palettes.
http://archicad-talk.graphisoft.com/viewtopic.php?t=53137
Have you installed the latest hotfix?
Not sure if it has been fixed there or not but always good to have the latest update installed.
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11