Yes, I thought I was the only one. I have a cervelo s5 with ultegra di2 and it absolutely shreds derailleur hangers. I've replaced 3 in the last 6 months and it never stays tuned up perfectly like di2 should.
I to had trouble with my S5 deraileur hanger.
The frame mount is so far out of aliment I had to twist the hell out of the hanger with the aliment tool.
Plus how tight you make the wheel shewers changes the derailer setting.
One thing I,ve noticed that people who shift will out pedaling are twisting the hell out of the hanger
because the deraileur motor stronger than the hanger ! They got in the habit of pre shifting before exiting a sharp turn which is no trouble with mech shifting.