Hello everybody,
oddly trying to rotate one of several HDRI Backdrops via blueprint does only work for X/Y (Roll/Pitch) but not for Z (Yaw). Also rotating the HDRIBackdrop during simulation directly via the transforms in the details panel works fine. Although this only updates the backdrop appearance and not the light being cast onto the meshes this still stumps me.
I started to blindfire at any rotation of the HDRIBackdrop and it´s components 
but wonder what fundamentals I am missing here … Any ideas anyone?
If you look inside the HDRI blueprint construction, you’ll see
which contains
So, you can put this in the event graph
To get the lighting right, I suspect you also need ( also seen in construction )
Thanks for the super quick replie @ClockworkOcean 
The rotation of the HDRi works perfectly fine now, but the recapture part still does not seem to work 
Do you have an idea why the later might be?
I would make sure you don’t have another skylight in the level?
Just found the solution :
You have to change the Source type of the skylight component of the HDRIBackdrop to “SLS Captured Scene” then it auto updates the lighting of the 3D models in the scene when the actor is rotated.
Thanks @ClockworkOcean for the support anyways as the proper rotation of the HDRI material was the first crucial step
