@Ivaylo I've resolved the issue by connecting my old router functioning as AP to the new Archer AX1500 LAN port. After that, I have access to the Internet on both of them. Now only the new Archer...

@Ivaylo OKAY... So I've disconnected the second router functioning as the AP and the AX1500 got access to the Internet! FINALLY! I've reconnected the second AP, and now, this one doesn't have access...

@Ivaylo Sorry for late response but I had to leave this case for a while to take on other responsibilities. Here's current status: Updated DHCP range to 192.168.0.4 - 192.168.0.249 I've performed...

@Ivaylo Is there other way to setup this router as AP? Maybe without switching to Access Point mode? Should I update the firmware if there are any updates? Maybe my TP-LINK Archer AX1500 is a faulty...

@Ivaylo I wasn't able to connect to AX1500 both using WiFi or cable but the router seem to be working (lights were on). I've performed reset to default settings, configured it as AP once again with...

My main router can see the AX1500 on LAN2 port no problem: