Server Crashes Whenever A Player Joins

I created a server for me and my friends to play on using the latest snapshot (18w50a) but the server is very laggy and crashes about a minute after any player has joined the server.

I've tried resetting the server.properties file and deleting the world multiple times but it results in the same issue every time. Lowering the render distance does not fix it.

I've also tried using a custom start-up script and allocating more ram to the server (up to 3Gb), but that didn't improve the situation either.

Making a server on 1.13.2 works just fine and does not result in a crash.