iMac 2015 (17,1) installed the 15.4 update - and my machine locks up (unresponsive to mouse / kb) just a few seconds after logging in.

Hi OCLP redditors - I am hoping someone can help me here. I had this iMac running 15.3.2 without issue. I took the 15.4 update - and that is where things went wrong. I have the latest OCLP (2.3.1) and root patches are installed - and the OpenCore booter is installed on the fusion drive without issue. No matter what I have tried - my UI locks up within a few seconds after logging in - it sure feels like a graphics issue - but I am not sure. Things I have tried so far:

Regenerate installer USB using OCLP 2.3.1. Re-install MacOS. Tried booting from the USB as well as the MacHDD. I have tried resetting PRAM. Safe boot DOES work ok - allowing me to at least get in and run OCLP changes as needed. However, every time my UI locks up right after logging in no matter what I have tried. I would hate to be forced to clean-install - as I have several licensed programs that I depend on.

Is this a known issue right now? Any ideas on what I can try to get the iMac running 15.4 properly? Thanks!

Author: @somed00d001