So one of my friends recently started up a MC.Eternal server through BisectHosting (I believe). However, despite having a good internet connection (upwards of 120 mbps) and getting good ping (tried pining the server both in and out of game, always around 30 ms) I get very bad server lag. If I stay in one position for a while (usually within a chunk) I can usually access chests and break blocks just fine but if I move at all it takes a while to catch up. And don't get me started on when I'm exploring and stop to mine a block and it takes a full 30 seconds to do so.
Anyway, I've tried many different solutions to no avail. I'm not even sure where the source of the problem is. I've noticed that if I open a browser and do an internet speed check with the game open I get <1mbps. That being said I don't have this issue with any other online games. Also during the first week or so that the server was active if I played during the day I didn't have any lag but in the evening/night I had issues. Now the problems persist 24-7.
2/4 of my friends are having this same issue except deleting and reinstalling the modpack doesnt fix it. I notice it only happens at our base, once you get around 1k blocks away from it or change dimenstions it doesnt lag.