(Case 1082192) Massive performance hit due to UI

Hey, sure but I believe this is the same issue
https://discussions.unity.com/t/715111
I posted in there notes for your team to reach out my project, that is already accesible to your staff for another issue.
I can send you PM with acces data if that eases things.

edit: OK

edit2 Unity QA notified me this to be same as
** (Case 1081996) **