Weard rotation in animation sequencer

Hello, I have a control rig for the player’s arms and I’m trying to animate them in the sequencer. But when I add 2 keyframes then unreal makes the hand move in an unnecessary curve. The hand looks downward in the middle of the animation.
Keyframe 1


Keyframe 2

Motion in between keyframes 1 and 2

I have considered it to be Gimbel lock based on this video (https://www.youtube.com/watch?v=_Mdq5EhJ56k&t=499s) but it wouldn’t make sense because I don’t have pitch/Y rotated 90/-90 degrees.