Does it work if you use SPACE BAR +ENTER instead space bar + mouse click?
And/or can you use it from the menu ... Design > Outline Polygon with Magic Wand
Does it toggle the Quick Select option (magnet) on and off?
If so it sounds like it could be a keyboard or mouse driver issue.
See the post here from when Nicholas Cornia gets involved.
http://archicad-talk.graphisoft.com/viewtopic.php?t=55009
If the space bar is not working for anything then maybe it is being 'hi-jacked' by another program running in the background.
Barry
One of the forum moderators.
Versions 6.5 to 27
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11