I figured this out from some other posts. This is 100% GOG and the overlay it uses causing the game to freeze up for 3-5+ minutes each time when starting up. Turn off the overlay feature in GOG settings:
https://www.reddit.com/r/BaldursGate3/comments/15itpk9/stuck_at_100_loading_screen/What is odd is that this was never an issue on release and a few weeks after. It only started recently happening.
