[GZDoom 3.7.2] Strange particle effect constantly rains around players

This felt like the right forum section to post this in as I couldn't find a dedicated GZdoom section, me and a friend have been playing GZDoom cooperatively on my home osted server for a couple years now, and one thing that we didn't realize and start getting very annoyed with until atleast one year ago is that there's a strange rain of particle effects constantly trickling down in a small radius around each player connected to the server, which also follows the player everywhere and nowhere - from the server startup to the end of the map, no matter which map or gameplay mod we use - vanilla GZDoom does it too.

A thing to note is that this also happens in single player when launching GZdoom straight from the .exe and not running any type of server.

It would be fine if it wasn't for the fact that it's always noticeable, and in darker maps it gets very distracting and headache inducing - I don't know why I haven't thought of posting on forums asking for help about it until now, but I've googled this a multitude of times in the past (and recently) and never found anyone else mentioning this strange particle rain effect.

If someone knows what the hell this is I'd love to know if it can be turned off entirely.

It may not seem so bad in the .webm sample I recorded below, but the more you play the more and more annoying it gets to constantly have follow you :P

https://gfycat.com/AcademicRealAmericancrow

That is the weirdest thing I've ever seen!  

I'm not a GZDoom expert, but I am not aware of any built-in setting that would cause that.  My immediate hunch is that you've got a mod or a scrip auto-running that you're not aware of.  Do you have any custom wads or pk3s in your directory that you might be running?  A fresh install of GZDoom is always worth a try too.

As an aside, co-op on GZDoom can be a bit risky as the source port can desync if packets are dropped.  Zandronum is a GZDoom forked source-port that specializes in multiplayer, and is a safer bet.  It's what most people use for more advanced-source-port multiplayer.

Check your autoloads in gzdoom-user.ini. Something's probably in there you forgot about.

Tick the "Disable autoload" checkbox on the GZDoom welcome screen when starting a solo game (with the IWAD selection list) and see if the problem persists. Logically it shouldn't.

Then lauch GZDoom normally, open the console, and scroll all the way up to see what archives it's loading (after the line "W_Init: Init wadfiles." there's a bunch of "Adding whatever.wad, xyz lumps" which tells you what data it loaded. You should find gzdoom.pk3 and zd_extra.pk3, then the IWAD such as doom2.wad or whatever game you loaded, optionally lights.pk3 and brightmaps.pk3 if you loaded them, and then whatever stuff is autoloaded, and finally any mod you explicitly loaded for this session, if any.

One of them is the culprit.