Shame on me for not having instant replay from geforce experience turned on, so the video is after I got there.
I was trying to get all tier 3 relics in one game. I had already completed blood vials and dragon trials, and while I was passing rounds waiting for ravager round (and almost dying) I threw a Kazimir to save my life and escape, but I accidentally jumped into it and got teleported to the boss room… with nothing there.
If that wasn't enough, it was my last kazimir, so there is no way back. Even though I didn't get the max ammo from the wall during the boss fight, I was running dragon wings so I can hear the power up, but couldn't see or grab it.
Save and quit worked, so I’ll try again tomorrow, but I’ve never seen this bug before.