I have the same problem on PS4, infinite loading screen at the start of this quest. I absolutely loved this game but this has left a very sour taste.
I bought the game at launch but decided to take a break to wait for the bugs to be sorted, here I am nearly halfway through 2020 unable to complete game. It seems there a cheat mod on PC to get through loading screen but consoles are screwed. I hope Warhorse patch it but after this amount of time I’m not hopeful.
For what’s it worth when I began recently playing again the experience was far better than launch (so much so that I bought DLC’s as thought game was fixed!). But the longer my playtime went on the texture pop in started to get really bad, I had a couple of other infinite loading screens but going back to earlier saves fixed it. It really seems the games performance deteriorates the longer I played.