Try to make sure that if you want to input behavior like shooting projectiles you have to do
if(Main.netMode != 1) ... I believe netMode 0 is Singleplayer, 1 is Server and 2 is Client. Not really sure though.
and finish it with a
npc.netUpdate = true; <- to send the data to the server. That fixed most of my issues related to multiplayer.
You can look into this part if you're curious.
https://github.com/Cheezegami/Mod-S...blob/master/CheezeMod/NPCs/GraniteWanderer.cs
There is a possible cure for multiplayermoditis?!
Welp, I'm excite.