text cursor jumps around but still types where it was
I've seen plenty of "My text cursor jumps around" questions, but in all of them, people mentioned being bothered as they inadvertently started typing elsewhere. That's not my issue: my Mac will still type where it was typing, the cursor will just jump upwards (no change in horizontal coordinate) for a key or two (this only happens during and is brought back by keystrokes, backspace included).
This happened through all the OSs I used and only in TextEdit and Notes (IIRC).
Any idea what this could be?
The note I'm writing at the moment makes this happen way more often than I've ever seen it occur.
MacBook