Archer C64 worked flawlessly (O2 provider with PPPoE connection type with login and password).

Then connected RE305 in OneMesh mode.

The Internet connection stopped. PPoE cannot connect.

Spend hours doing adjustments: removed SmartConnect, switched on/off DHCP servers (auto, yes, no), played with IPs, rebooted bother devices several times - nothing helped.

When RE305 disconnected - then C64 connects well (after reboot) and the internet is ok.

When connected as a range extender (not mesh) - the problem persists, but I have not tested it thoroughly.

Firmware of RE305 and C64 updated up to date.

This RE worked well with another Archer router (don't remember the name), but the connection to the provider was different (not PPPoE).