As soon as server launches, resource use shoots up to 100% for both CPU and RAM. Server will run for fifteen to twenty minutes and eventually take so long to tick that Server Watchdog shuts it down. Even setting max tick time to -1 or 999999999, the most the server's running for is 30 minutes at a time before crashing again. I'm not the only one this is happening to:

https://www.reddit.com/r/Minecraft/comments/bgkrh0/114_server_frequent_lag_spikes_was_fine_for_the/