Don't know if this has already been said or not, but I was doing the boss rush in the final tower and I made it to the phaseman part, but was standing on one of the platforms in the very back against the edge, and when it transitioned to Gun-D4m I fell off the screen along with part of the platform and I couldn't do anything while the boss continued to attack and kill me. In testing, it happened pretty consistently in the corner shown in the video. It's on hardmode, if that makes any difference to normal mode.
https://streamable.com/fbd5m6
https://streamable.com/fbd5m6
