I don't think this one has been addressed here yet.
I have a simple fascia and yet I struggle to get it to act correctly. I have modelled a roof as a 50 mm plate to just represent the tiles, the other elements I can deal with later. The existing condition has a raked fascia and a raked soffit, basically following the rafter feet.
I can rake the mitre but no matter what I try with the mitring options it won't mitre as I want it at the junction between the gable and eaves. This is all done using the stock fascia profile, it that effects things.
All help gratefully received. N/S GSOH MWM etc.
P