Version: 5.0.0-prealpha (git a4ec3b3)

i like to use alt to color pick when i paint over something. i press alt up to 2 times a second probably, switching between making a stroke, color picking and making another stroke very quickly.

i noticed for a while my color pick shortcut can just stop working after using it too many times. this only seems to happen with pressing alt. ctrl works fine. after it stops working, pressing shift makes it work normally again.

while alt doesn't work, other canvas inputs seem to also be broken: spacebar to pan for example.
undo works fine in this case and so do other controls under the "keyboard shortcuts" category


i'm unsure if that's relevant, but the way i set alt up as my color picking shortcut was by making another entry in the canvas input settings. 
(i have the "switch control/alt modifiers" checkbox in [settings>configure krita>general>tools] unchecked.)

STEPS TO REPRODUCE:
1. go to canvas input settings
2. new shortcut: mouse button | alt+left button | pick foreground color from merged image
3. press alt repeatedly
->the color picker shows up less than half of the time (it doesn't work when it isn't visible)