Mobs in servers effected with more than 1 person online

Title says it all.

I have a server running the 1.16 release candidate 1. I have 3 people that play on it and when its only one person online the spawns for that person are fine in a Creeper farm or a Skeleton farm or even an Enderman farm but as soon as someone comes online and in the same world that I'm in (overworld, the_end) while I'm at the farm and they are not in the same chunk as me, the spawn rates are EXTREMELY LOW if any at all. Not quite sure if this a bug but I haven't seen this before on 1.15.2.