Huge lag spikes in maps only

I just started my first map and it's unplayable, I'm on series x and tried every settings possible. I can't play in maps. Insane lag and stuttering and it's just T1, there's not a lot of mobs. I'm on the right server for me, my internet is fine. I tried reseting my modem, Power cycled my Xbox. Really disappointing, guess i wont play much further....