Huh?

So i was doing a survival platinum run, but on wave 8 for some reason the last enemies froze, still taking damage and dying but respawning instantly, everything else worked normally, i figured i just die by exiting out the map, i do it and the timer runs out but doesnt end the survival, what the hell just happened?

https://preview.redd.it/bi72bn2zytvd1.png?width=1920&format=png&auto=webp&s=4920ed701326ad5a3f75dcb7ecb04e5c58baad66