Boss health config change causes really bad lag

So in my 3 player modded calamity server, whenever someone changes the boss health configuration, the health changes fine. But whoever adjusts the slider experiences really bad lag with the bosses. Their projectile attacks are usually completely fine. However their sprites and any dash related attacks lag out like crazy and teleport all over. With cryogen he wasn’t even in his shield. It was floating below him.

If we all change it. We all lag. If one changes it. Only the changer lags and the others don’t. Really no clue how to fix this outside of checking for mod conflict but i can’t do that right now im on a short trip.

Mod list is:

Magic storage, calamity, Cal vanities, cal musics, infernum and infernum music, sub world library, head follows cursor, alchemist NPC, lights and shadows, recipe browser, no biome spread, boss checklist,

Update: if it matters. While on a host and play world if I’m solo it doesn’t lag. But while on my server even if it’s just me online I lag.