As someone mentioned above, there are some soho devices I have run into that plainly just won’t work with IPv6 even though they claim to and will pull a lease. One or two I have seen just seem to stop working simply by having v6 enabled. Hours of troubleshooting. Its worth making sure someone in internet-land at least claims v6 works on any persistently trouble some devices.
Cheating is still common and demonstrable despite their anti-cheat rootkit, and their match making logic could use a material revision for casual eg Premade of 2 != Premade of 5