@Joseph-TP No interference from Neighbours checked with the channel. Router is placed at the center. And channel width is in 80/40mhz. So everything you said is done but still the problem exist.

So after updating to 1.2.1 my archer ax12 is not working as it was before. Whenever I connect in 5ghz it works perfectly for some time then out of nowhere the internet would cut off. This happens...