Oh, I'm sorry for the late reply, I didn't see your answer. I'm not a big fan of sitting in the discord, so I'll just wait for the release of the new version. I'm currently going through the Arena on maximum difficulty, and I think I've found another bug: it's impossible to pass Jibril on maximum difficulty because she just doesn't die. As you can see in the screenshot, she was actually defeated, but still remains on the battlefield, which is why mobs continue to spawn endlessly as the game thinks that the boss is still alive. All other bosses (except doppelgangers) I passed. Jibril doesn't disappear on a permanent basis, I tried to go through it three times, but each time she didn't disappear.
