Hi, I just found out that a rotator’s Pitch value is limited to -90 / +90 (that can be checked in the editor while rotating a mesh). Additional rotation is converted to -90/+90 by offsetting Yaw and Roll by 180°. This is very painful when working directly with rotation components. I’m working on a…

How to fix the rotator pitch bug

birdfreeyahoo (birdfreeyahoo) July 11, 2014, 3:21pm 2

It is a confirmed bug and will be fixed, but there is no ETA given.
Look here for further information: