My friend keeps getting kicked about 5 minutes after joining my multiplayer world.

Every time I load up my multiplayer map I created one of my friends keeps getting kicked. Before this version we had no issues with this, but now we do. I do have a lot of command blocks loaded and as far as I'm aware they don't cause lag or count as entities. This bug also occurs when I join their worlds as well. It usually occurs every 5-8 minutes and also happens with some of my other friends too.