Keyframing camera transform is not acting as usual, why?

Hey there !
I’m having issues with just the simple animation of the location/rotation of the camera in the sequencer. For some reason I don’t yet understand, whenever a keyframe is set to “Cubic”, the footage will stutter like crazy for no apparent reason. It never happened to me before.

The only way to “fix” this is to set said keyframe to “linear” but then every change in motion will be very noticeable and not smooth at all.

Also, when I apply keyframes for location and rotation, the camera just spins on itself very quickly… Like the “yaw” is actually making a full 360° spin whenever a change in the rotation of the camera occurs.

Yeah… it’s hard to explain because it’s super weird.
Here’s a video to help you see what I mean a bit better (hopefully) :

Any ideas would be appreciated ! Thanks.