I am unsure as to how to test the modem, is there a way to login to the modem? The OpenReach engineer just pulled the modem outta the box and it was plug and play he didn’t do any setup(could be pre configured but when I spoke to him about the by internet change he said the exact same as you it should just be plug into the modem and no problems
No, its locked so you can't access it.
I'm not familiar with the MT992 but I'm surprised it has an 'Internet' LED as this would normally be on a router rather than a modem. Did the 'Internet' LED light when you used it with Sky?
I’m sure it did but I’m going to have a quick google search see if I can find anything on it. If the light doesn’t come on what other troubleshoot options do I have?
I'm not convinced the 'Internet' LED should be lit.
I would factory reset the Netgear to give a clean start and then run the setup wizard entering the PPPoE details when prompted. Ignore the VLAN ID for now as the modem should take care of that.