Frame rate issues on console during multiplayer?

I've been finding multiplayer to be kind of unbearable. When there is a full party the frame rate goes to absolute shit and the game will also be very laggy. It's pretty bad even there is a Witch in the party with a minion build because the extra minions in the screen will also cause the frame rate to delay.

Is this a known issue with console? I also noticed that the instances will randomly hop to locations like Singapore when entering a new area. I am in the U.S and I want to know if there is a way to region lock so I only connect with players from North America. The lag plus frame rate issues has become unbearable for me to want to play this game online.

I've even started only running with parties of 3 or 4 .. I do not enjoy this game when there is a full party, especially with how much bosses scale to the party size.