I aded 41 keyframes by either plain drawing, duplicating or editing other keyframes, the thing is, when I try to add keyframe 42, the keyframe 41 appears on top of it, and this happens for every new keyframe I draw.
The only new thing I added was a new GP layer above my original layer, and if I erase it, it also disappears from all previous keyframes.
I tried searching other questions with this issue but I don't seem to understand anything, I have some experience modeling and sculpting as well.
Also: this has nothing to do with onion skinning as these only appear when drawing new frames, not when hitting the spacebar.