@StuartP I am from India and bought this router around January this year. I am currently on 1.3.5 Build 20200630 rel.57406(4555) firmware with Archer C6 v2.0 as HW version. I started facing the same...

I can now confirm for sure that my last changes have finally stabilised my router with absolutely no drops in any band in the last 2 weeks. Reiterating - Disable Smart Connect, keep different SSID's...

Things look stable now with Smart Connect disabled and both bands enabled with different SSID's. New devices connect to the 5G band and the rest connect to 2.4G band.

@SubhX I bought the Archer C6 v2 in Dec'19. I had an OTA firmware update (1.3.0 Build 20200402 rel.52000(4555)) last week and post that I seem to have the same problem. After enabling Smart Connect 3...