im having issue with my vanilla and modded creative rust server freezing randomly.  it seems to happen when a player joins. both on a vanilla server with 3 plugins. and a modded one. the only comman plugins are Permissionsmanager,  Admin radar and advert messages. 

CPU sat at arnoud 20% ish. not overheating or anything. not running anything else.  tried unloading stuff. but cant get it to replicate... just seems kinda random - any tips? or maybe things i should check? or anyone else having any issues. only been happening last 2 weeks or so. 

Thanks.