Hey Bojan, thanks for your advise! But somehow the bug is gone. I started PS this morning and the Handtool/Spacebar works as usual. I didn´t change anything or restarted my mac. Strange! Have a great start into the new week!
On Windows everything works fine. Have you tried to update to latest 22.5.2 version of Photoshop? Perhaps there is some conflict and some other app is taking that shortcut? Another thing that can help when Photoshop starts with strange behavior is preference reset.