Pitch rotations > 90 in blueprint Transform vars

In a blank project, create a blueprint with a Transform variable. Set the Pitch (Y) rotation to a value > 90 and then try to set one of the other two values for rotation and see that they don’t set correctly. Alternatively, set either of the two other values to anything and then try to drag the Pitch rotation past 90 and observe it go nuts.

Happens in the blueprint itself or setting on an instance, and happens with both dragging and attempting to type values in directly.

Rotation is limited by euler angles, kinda complicated stuff but its effects are easy to see - and its probably what you noticed.

wiki on it: Euler angles - Wikipedia

If you have a 3d program installed you can check this working a bit easier by setting your rotations in the program to enforcing euler angles, usually referred to as using “gimbal rotations”, or “gimbal lock” etc.

Hope that cleared it.