What is the elevator bug, are there special places/elevators where it does happen or can it be any elevator?

I have currently parked my Honour mode playthrough before Orin and the brain, all other fights done, and started a new playthrough with Custom mode and some mods. Maybe I will finish Honour mode later, but I lost steam.

As I played the most part of Act 3 for the first time in the Honour mode run, it was an interesting and fresh experience. Quite intense. I was very cautious and anxious overall and often decided to run instead of fighting it through, also because I did not know what to expect. From some fights I ran without good reason, like Ethel. In some fights it was a bitter necessity. With Ansur for example I had to flee two times to avoid a wipe before I managed to win on third trial (the only instance in the game so far where I used Globe of Invulnerability). Some bitter experience was when we almost wiped in a minor fight against undead because of a mean curse they used. Only because Shadowheart was out of the fight at start and could change spells, we survived. The fight against Raphael was long and difficult. Hope died and strangely I deeply regretted to have killed Raphael, it broke my spirit to play further to a certain degree.

What I have noticed now in my Custom run is how differently you can approach combat. In Honour mode I used Cold and Lightning a lot together with the vulnerability from Wet, and had some concerns about the cheaty aspect. I avoided to use Haste mostly. In my current run the vulnerability from Wet is modded out, but for the first time in game I started to use Radiance, Reverberation and Arcane Acuity which I totally ignored in my Honour mode run. And they make life even easier than the Wet nonsense because enemies are debuffed (which is really needed now) and control spells become so strong. I now can understand why some say that Honour mode is easy.

Luckily I had only one crash during Honour mode, with no bad results. BG3 for me is an extremely stable game, since start of EA I had only 4 crashes. No noticable bugs so far. I feared Error 516 which I had in my first playthrough in Rivington, but it did not appear.