On those two systems, plugging in the Fable Hub is only the first step to using it. You also need to manually connect to the Hub via Bluetooth. Tap the Fable Hub icon at the top right corner. This will take you to the connection screen where you’ll be able to connect.
You need to run a critical update to your Fable Hubs.
Please contact email@example.com for assistance on how to update or if you still cannot discover the Hub even after updating.