Whenever I play single player, my health (the overlay on the top left) always shows. However, if I join my server, it will show the first time i join, then disappear when I rejoin. Only way to fix is to have the client config in both the server, and client, then edit the server's client config and save. It's really stupid, and didn't happen in previous versions. 1.20.1 Forge btw.

This sounds weird. Are other mods involved in this? Does this always happen if you reconnect or only sometimes?