SUMMARY
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After you open a combo box in a docker or on the tool bar and select an option (Brush smoothing in tool options, layers modes in the layer docker, brush groups in the brush preset docker, and color modes for your current brush) or change a checkbox, space bar keeps interacting with the combo box or the checkbox instead of panning or zooming in an out. You have to interact with the canvas first in order for the space bar key to stop interacting with the dockers. It is worst when repeating keys are enabled on the system.
***


STEPS TO REPRODUCE
1. change either your brush smoothing, layer mode, color mode, or any other option in a combo box or checkbox. Or just interacting with setting withing dockers
2. move the cursor over your canvas.
3. hit space and or hold it.

OBSERVED RESULT
Space bar will interact with the last element you clicked in options within a docker

EXPECTED RESULT
Space-bar or Ctrl + Space-bar would just pan or zoom with just having the cursor on the canvas.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: Kubuntu 22.10
(available in About System)
KDE Plasma Version: 5.25.5
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.6

ADDITIONAL INFORMATION