To duplicate this, download the wad from: https://www.doomworld.com/idgames/level ... m-o/osiris and run GZDoom with osiris.wad and osiris.deh. Start a new game on MAP01. Enter the console command "warp 5989 -2157 32" and walk towards the blue portal. You'll hear the "Now human you shall die" voice clip but it repeats forever until you move out of the area. There's a similar issue in MAP02 but it just repeats forever for the rest of the level?

Anyway I found a YouTube video if you want to just take a quick look (start at 9:21): https://youtu.be/UXymywtFG90?t=561
It doesn't seem to occur on any other source ports, including ZDoom 2.8.1. I downloaded some old versions from the archive and narrowed it down to GZDoom 2.4.0 where it starts - version 2.3.2 works just fine.