Hence see what conditions the hub indicates when not using the hybrid.
I'm not sure if the hybrid kicks in if there is an account type problem or only if the WAN physical input fails. I think it is probably just the latter, in which case the problem is either the patch lead or the hub itself.
I assume you have tried a different patch lead.
Hmm, just re-read your original post, there is no mention of rebooting either the ONT or hub. I would try doing that if not already done so.
