Convexa S repeater won't connect to Orbi

I have found numerous reports here of issues with the repeater mode and refusing to connect to hotel networks etc due to an ongoing DHCP incompatibility issue. The outgoing DHCP request is seemingly met with no response and the router reports a timeout.

I am getting this with a Netgear 850 Orbi setup. I’ve tried switching off all nodes except one, tried switching off 2.4GHz. No difference. They won’t talk to each other. It will work with my S21 ultra mobile hotspot but that’s not what I need.

Is anyone looking into all these DHCP problems as they seem to be widespread?