I've bought an AX3000 recently in the hope that I might be able to mesh it with my existing C6, just so I could keep it as a "backup" but with better coordination on which devices connect to which.

Set up the AX3000, factory reset the C6 and... the AX detected the C6 on LAN, but when I started pairing it as a satellite router, after some thinking, it just threw some unhelpful error. Tried both connecting WAN port to existing LAN and (after disabling DHCP) LAN to LAN. Also tried switching to AP mode, but then I've read that routers in AP mode just won't create a mesh yet.

Could this be because the AX tries to force the wifi6 settings to the C6 as well as the 2.4 and 5 GHz settings? Has anyone met with similar issue?

Thanks in advance!