The way arcs and circles are selected has changed in different versions.
The centre point used to be ignored unless specifically clicked on which I think was better.
It has been discussed in this post and it looks like GS may be looking at it.
http://archicad-talk.graphisoft.com/viewtopic.php?t=53430
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