Every 5 minutes (almost exactly) my 1.16 spigot server "stalls". My CPU usage dives and stays down, implying that the fault is on the server. During this period, the server lags and/or kicks everyone off. I don't believe it's a plugin issue.
I guess but it started a bit after the initial creation of the server and happens regardless of if anyone's online and has been happening for a whole day now so I doubt it's chunk loading issue if that's what you're implying.