A lot of Users can’t play Halo 5 Arena/Warzone/Custom since the NXOE is installed.
Pls help 343!
I am having issues as well. Been trying to research an answer for a couple of hours with no real findings to report
I have had no issues 
contact MS support
MS support isn’t really helpful at all
My Provider switched my Router/Moden to IPv6 without my approval.
They turned back to IPv4 and now everthing works fine.
Can Play Halo 5 online!