Hi peeps. I hope someone can help me or give an advice. I bought a few days ago an AX3000 aka Archer AX53. I live in Ireland and I have Virgin Media 1gbps.(with my Note 10 plus next to the ISP router I get around 500 mbps on 5ghz and 55 mbps on 2.4ghz, however the router does much worse when distance is a bit bigger and occasionally connection is lost, reason for which I bought a more decent router, or thought so). I had to connect the AX53 router with ethernet cable to the ISP router. The AX53 does much better at around 800 mbps on 5ghz and 150 mbps at 2.4ghz and holds better at longer distances. On both routers the ping stays  between 15/50 most of the times, rarely less than 15 and in rare cases goes even over 200. Both routers are updated to their latest firmware.

The main issue is when I try to connect an extender to the AX53. I've tried a Netgear extender, an AC750 (v1, without mesh) and an AC750 (V4 with mesh). As soon as I connect them to the AX53 my internet doesn't work properly anymore, extremely high ping, low download speeds, unable to use speed tests, some images on websites are blocked or interenet doesn't work at all,  with the only exception being the AC750 when I use the mesh, but in that case the internet stops working when I use an Ethernet cable from the mesh extender to a PC/laptop. If I connect any of the extender to the ISP router ( without having the AX53 connected) they work and I don't experience any issues, until I plug the AX53 Ethernet cable.

Now not having an extender it's not the end but what makes matters worse is that the same issue happens whenever I try to connect other devices as well, like one older laptop and one PC which has an Archer t4e ac1200  PCI Express adapter, this only on the AX53, again no issues on the ISP router.

Errors that I get are "a socket error occurred during the download test. a firewall could be blocking the connection or the server might be having some issues. please try again later. tp link" or another  one that makes similar reference to the firewall. 

I've tried to disable firewall on both modems and it seems to be working better for a few min, even giving more speed surprisingly but then it stops working. 

What I've seen on other forums is that people with Virgin Media that buy another router they transform their isp router in a modem from the settings, unfortunately I don't have that option as Irleand uses  IPv6 , in UK they have ipv4 and they have the option.

-Could the fact that I'm basically using 2 routers at the same time be such a big issue?

-Any particular settinggs that I should do in either of the routers?

-Should I send the AX53 back and buy something else? 

Any help or ideas would be much appreciated, thank you!