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You need to set your Orbi RBR50 WAN port to have a VLAN ID 2 tagging.
Check the discussion of other customers who was able to set their Orbi device via NBN HFC. Here's the link: Netgear Orbi Connection Problems.
Please note that the VoIP home phone will not work on a third party device.
Let us know should you require further assistance.
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