Since 21w19a when Java 8 was replaced w Java 16, my server just fails to stay open when it fully boots up. Logs aren't of much use as the server doesnt indicate that it has shut down, it just does. It's as if the server is killing itself as it finishes booting up. Playing singleplayer and running a LAN server then running an ngrok server works just fine, but an actual dedicated server just says no, basically.