Archer C6 v2 in AP mode - how to set up OneMesh network with RE300
I have Archer C6 v2 that works in the Access Point mode (connected to router provided by my internet provider). I've tried to setup a OneMesh network with RE300 but Tether App (RE300->Tools->OneMesh) displays message informing that my router does not support OneMesh. When checking Archer C6 menu (tplinkwifi.net) there is also no option for creating OneMesh network.
I've checked that everything works flawlessly when I switch Archer C6 to the router mode. After switching to this mode it took me less than a minute to create OneMesh network with RE300. It was possible via the website since 'Advanced' menu is available in the router mode.
Can you please advise how to set up OneMesh in the AP mode? I can't imagine that it works only in the router mode. If so I will need to return RE300, scrap Archer and find another working & reliable solution.
P.S. I've tested also some previous firmware version with no success.