Frequently cursor becomes stuck as grabber tool

About one in three times I start Painter 2017 (on Mac OS Sierra) the cursor is stuck as the hand grabber no matter tool I select. The only thing I've found that fixes it is restarting the Mac.

These things do NOT fix it

- quitting and restarting Painter

- starting Painter with Shift to reset all workspaces

- starting with no keyboard plugged in (in case the keyboard was sending a spacebar)

The frequency with which this happening is a giant drag on my productivity.

The only thing that might be unusual about my Mac's configuration is that I have Karabiner Elements installed (a program which allows remapping of some keys). Simply exiting Karabiner does not solve the problem once it has already gotten started, but I need to eliminate Karabiner entirely for a few days and see if the problem recurs.