I doubt this has been fixed on 5. This bug exists for several years by now. I can’t even recall when I started to have this. Still have not tested it on 5 but will take a look.
Space + pen tap the release at the same time.
Though mine only does it after i put my pen back the first time [after the spacebar +tap] then draws if i lift the pen for even a little then draws again it goes to normal.
What i notice when i replicate: its when the spacebar is press while the cursor is till arrow and not brush right at the pen tap.
since i always lift my pen right after i activate krita [a habit] - i barely notice it.
Overall Krita on Windows is having this issue with modifiers keys, if you enable the Log Viewer docker you should see the message: WARNING: modifiers state became inconsistent! Trying to fix that...
Hello I wonder if this behavior is also part of this bug.
Right Click > Popup pallet > pick color > click on canvas to draw > cant draw or color / brush outline not visible > right click again to activate brush outline. [sometimes it activates by lifting the pen up a bit]
[found on 4.4.7, 5.0 beta, a late august 5.1.0 pre-alpha, and Sep 17 5.1.0 pre-alpha]