What’s happened?… :-(

I have two PCs NAT’d behind the router, and they would happily play Battlefield 1 for AGES. Suddenly, Thursday, this was no longer possible. I didn’t change anything, but connection could not be made. Originally I had nothing “exciting” set up on the router, UPnP seemed to have worked for all my gaming needs, and now nothing. I wonder if a router firmware upgrade happened that’s now broken this behaviour?… (Zyxel VMG8825-T50 - V5.50(ABPY.1)b15_20201207)

I’ve tried:

1. Restarting the router.
2. Factory Resetting the router.
3. Resetting the networking configuration on both PCs to “Windows 10 defaults”.
4. Reinstalling battlefield 1.
5. Reinstalling windows 10.
6. Giving static addresses to the PCs (disabling DHCP).
7. Trying various DNS servers for the PCs.
8. Configuring port forwarding for all necessary ports (UPnP On)
9. Configuring port forwarding for all necessary ports (UPnP Off)
10. Forcing clientport for the two BF clients.

Nothing works, just occasionally I get a little “further”, i.e. the game might at least consider itself “online”, but then it can’t find servers, or can’t ping servers, or cannot actually join a game.

pingtestlive.com is showing a VERY long ping time for the NL server, > 250ms, which would certainly cause this issue.

I also have t-mobile cellphones, and switching them into hotspot mode and gaming over WiFi via them *works*!

So the fault is with the router, or the router interconnect into the t-mobile network.

I’ve spent four days trying to resolve this, but with no success.

Same problem, but on Playstation. Glad to read this, as i was starting to think i was crazy somehow