Set Rotation Never Works as Relative/Local

Hi Having a major problem with applying streaming LOCAL rotation data to an Actor.

Set Relative Rotation always applies the data as World. Set Rotation also always applies the data as World. Set Transform the same etc.

How is it possible to actually apply LOCAL rotation data to an object??

Our test case:

Start actor at P:0,Y:0,R:0 (Pitch yaw roll) turn actor P: 45 moves actor up pitch 45 back to 0,0,0 then yaw 90, actor turns yaw 90 then (LOCAL PITCH) pitch the object 45 and actor ROLLS 45

HELP please!

PS: have tried all forms of data (matrix, quat, rotator with the same result. Source data is CONFIRMED to be working as local and is a matrix)