It will come online, don’t worry.
When initially turning it on whilst connected by Ethernet cable the centre light will eventually become solid blue to say it’s paired with the hub and the bottom signal bars will also turn blue. Once this has happened you can then unplug the Ethernet and just set it up elsewhere in your home.
You can place the hybrid anywhere (except in a cupboard of course) and just forget about it because all it is, is a fallback contingency device for if your hub loses its ADSL/VDSL signal, it will then kick-in within 2-3 minutes and your hub will then turn purple. The bottom signal bars will turn white if it ever has to fallback onto cellular 4G network.
likewise, once your hub discovers a ADSL/VDSL signal it will go from purple back to solid blue then the Hybrid signal bars will turn back blue. From this point your Internet connection will be back up and running.
You can check the status of your connection on your BT App or by typing the IP address of your hub into a browser on a phone, tablet or PC/Mac internet browser.
I’d suggest power cycling your Home Hub and discs when you make any changes as this will refresh any addressing records on the devices.
Hopefully BT will have the correct IMEI number of your hybrid device on their records and you’ll be all online soon.
