Physics object get world rotation returns strange value

Hi
I’ve added a collision capsule with physics enabled and with all locked but Y rotation but even though the physics object keeps rotating in the same direction the get world rotation returns a value that goes up from -90 to 90 then even still turning the same direction the value goes back down from 90 to -90.
I wanna turn another mesh getting the rotation from the physics capsule but the mesh only makes half a turn one way then back and forth only making half a turn ever.
NB. I can’t make the mesh a child of the physics object.