Players get kicked out of server if accidentally pause the game

I had an old world then my nephews started to get kicked out every time they tried to log in. I thought it was because of lag so I basically destroyed my base and turned off most mobs and resources when they were here, they still couldn't join. So I had to make another world and it started kicking them out from there too, even if the world was new. Then I noticed in a 2 day world that while they were loading in I opened the map and after that they couldn't join me anymore. It said they joined, but they were still loading. Then the game would crash on them. After they got kicked they couldn't get back in at all. My game has auto pause on and usually I have to go to where they are when they login to give them any supplies they might need.  Especially if they goin in a season other than autumn.