I changed the speed on a motion clip to make it slower (longer in time) this is causing the paste of motion layer keys to end up at the wrong frame.

Reproducible bug:
Change the speed of a motion clip to go slower.
If you double click on the top of the motion layer new keys will appear where the timeline indicator is.
Without moving the timeline indicator, if you copy that new keyframe and paste it, it will end up pasting further down the timeline. That's not suppose to happen, that would be too confusing on a complex animation.

How I discovered it:
(see attachment) I copied the 4 keyframes on frame 1308 move the timeline indicator to 1363 where I wanted to paste it and it ended up at 1383 instead. I suspect it is pasting not where the timeline indicator is but instead pasting at the motion layer's timeline prior to its resize location.

Comment:
Honestly, I wish you would not resize timeline columns to begin with, I would prefer the motion layer to be scaled and have the keyframes place to a new frame location.