Nether and overworld crashing with major roll ack

For about a week now our realm has been crashing atleast every hour and we get like a 5 minute rollback, but when someone starts mining too much in the nether, the game crashes and we can see an entire 30 minute rollback. We had a gravestone mod and a tree chopping mod and we removed both and saw no improvement. It is a real shame that we can’t experiance the nether and it is about to kill our realm. Shame to have all of our buds buy the game and us pay for the realm for it to end like this.