When I press spacebar to 'playback and pause from current frame', the playhead does pause, but when I press spacebar again to resume the playhead skips ahead, with increasing jumps ahead the more I press space to pause and resume.

It almost makes the program unusable.
I've included a video to demonstrate.
I've tried assigning a different shortcut key (eg 'C' instead of 'Spacebar'), there's no difference.
How do I fix this please? I imported my keyboard shortcuts from another computer in case that broke something.
https://youtu.be/95FYgh7ewUA
Please see video above that demonstrates this behaviour in all TVPaint projects.