Ok, so I have my lovely Netgear XR500 with GeoFilter and have recently upgraded the firmware from 2.3.2.22 to 2.3.2.32
After a few weeks of going nuts, and tweaking the GeoFilter + QoS, I could not work out why I was not doing well on BO3 (Xbox 1) .
Then having a look at the Netgear Community, I noticed a thread between a user and NutDuma and they have confirmed back in September, that indeed a bug exist with Firmware release 2.3.2.32 that is causing slow speeds and Xbox would be taken offline if GeoFilter was enabled and poor matchmaking etc.
So just loaded Firmware 2.3.2.22 and so far, gaming (console) is so much better ;0)
https://community.netgear.com/t5/Nighthawk-Pro-Gaming-Routers/GEO-FILTER-FILTERING-NOT-WORKING/td-p/1637236
Good news they (NetDuma and Netgear) are working on issue, bad news, still an issue a month later with no new firmware ?
In a completely sane world, madness is the only freedom (J.G.Ballard).