I see you’ve already found the main topic on the issue (here). I had the impression that for most people the occurrence has been random, but it could be that it has a higher chance of appearing when the phone has been under higher workloads for a while (an the update seems to be quite a lot of work for the phone). That would explain why for some people it occurs after the update.
As it’s not a general problem with the update, it’s probably best to keep the discussion about the screen in the linked topic for now.