I did almost the same thing. Started Terraria alone, nice and calm, then invited two friends and suddenly it turned into nonstop boss attempts and ridiculous builds everywhere. My local setup just couldn’t keep up and everything lagged hard during fights. We moved to Supercraft after that, using this page https://supercraft.host/terraria-server-hosting/ . Since switching, multiplayer has been way smoother, even when everyone is online and chaos mode is fully active. It let us focus on building and surviving instead of fixing server issues.