When using the left and right arrow keys to go back and forth through the animation timeline, if you have something selected it also starts moving the selection.

I tried reassigning the keyboard shortcut (it said that the default was "none") for next/previous frame to full stop and comma (like in Flash/Animate), but the arrow keys continue to control the timeline...this may be a bug.
I am using the Linux version with Kubuntu.

previous/next frame is controlled by settings->configure Krita->canvas input settings.