Xbox Live party chat and MTU problem

[Dubs]

Hi, i have been using Three 5g for a week now and while i am very pleased with my DL speeds, i cannot join people in xbox live party chat. The xbox says i have an mtu problem. I have tried port forwarding, putting my xbox in the dmz and turning off the firewall but nothing works.

[DrGravity]

What firmware do you have on the router? You can see via the app or router settings and the version will end with bXX (where XX will be a number). I'll wager it's the latest b14 version.

The MTU issue has been present since last year and does impact gaming but it never prevented Xbox parties before in my experience. I've had the same problem recently since the router auto updated to the b14 firmware. It seems to have broken UPnP / port forwarding

[Dubs]

Hi mate, i have the ZTE MC801a and am on B15 

[TheJunglist]

After trying several different things static ip>add to dmz, port forwarding etc with no joy. I've resolved the issue described on my son's xbox series s by enabling UPnP in the router's settings, then by selecting a different port on the xbox the NAT type went from strict to open and issue is resolved - You may have to try a few different ports, luckily it was the first port I tried!  Hope this helps 

[CSpec01]

I've tried this but sadly it only works within a few seconds of updating the router settings to UPnP enabled. Giving it some time and testing again shows the issue is still present. 

[Neverworksright]

So after 2 years of playing a lot of Xbox games online with voice chat I now to have the Mtu issue and after calls to Xbox and zte I painfully clear it’s a 3 issue and to be fair as usual the call centre staff were useless is this ever going to be resolved?

[crabmandoo]

I have the same issue, have you found a result?

[Neverworksright]

It’s to do with the mast as mine now works again nothing changed 

[JonathanB]

Thanks for confirming this @Neverworksright, that seems to line up with the testing and research I've done too.

Unfortunately it does seem to be an issue caused by either signal strength, or congestion in the network. The network's MTU is 1500 in normal conditions.

There's a couple of things that may help, UPNP enabled to help give an open NAT, using an Ethernet rather than Wi-Fi if possible, the router being positioned as optimally as possible, however coverage, network maintenance, and contention between multiple users can still cause this to happen. We're always investing in the infrastructure though, so hopefully there'll be less of this issue as time goes on.

Thanks,
Jonathan

[Shhsjd]

Any confirmed fixes? Same problem, party chat not working