Server OS: Xubuntu 18.04 LTS  Minecraft 1.14.x versions run really unoptimized with chunk loading issues using far more cpu usage than older versions 1.13.2 and under which will barely use the cpu on idle while 1.14 and up seem to hit the cpu really heavily.   E.g a server with 2 cores and 4gb ram would run minecraft 1.13.2 no issues but minecraft 1.14+ hit one core to 100% for no reason at all times when running