The last part is true cause I started mining stone and I fell in void and when I did /is, it didn't work and I fell to my doom. RESTART IT PLEASE OMG OMG OMG OMG OMG OMG OMG OMG PLEASE I BEG OF YOU PEOPLE ARE SPAMMING LIKE 200 WORDS EVER SECOND I seriously recommend that you have a restart every now and then because that place is like the chaos of every server lag out there.
There already are resets like twice a day..I'm pretty sure at least. Maybe its not net it's your computer or wifi idk.
I'm not sure but this can happen when players mine blocks (that are above void) on their islands. For example, blocks that are floor/ground/layer blocks that are above the void (if you get what I mean) When you mine these it creates a short lag. Now if I'm not wrong, when these are mined players' client has to render what's below them which is nothing but the void and strange as it is it creates a lag spike. This also can happen when you're placing blocks.
Some servers have a command to /vote restart. Once a sufficent number of people vote yes in the past 15 mins and the TPS is indeed <10, Then the server will restart after the broadcast is announced 5 mins b4