Firmware got updated to last night to SG4B1000E016 but the Hub Manager in Advance settings and the Status on the Home screen says updated on 28th Novermeber 2018 ! Strange.
From what you have posted if it was mine I would do factory reset to ensure new firmware updated correctly
One step at a time, first off do a simple restart, if that doesn't work then backup the config file if you have any custom settings then factory reset. Once reset simply reload the config file to get all your custom settings back
OK, so I did a Restart first and the date did not change. Next I did a Factory Reset (pin button at back) and still no change in date. Did a seceond Factory Reset and still no change.
So the hub is showing incorrect date of Firmware installation. Do BT actually test the Firmware prior to release or are the Hubs so vunerable to glitches?
Having said this, my Hub has been reliable since installation in 2016 and has been the best hub so far (I've had them all), but it certainly does not live upto BT claims in their independant tests.
Despite the hype of the TV adverts good BT hubs are few and far between, I wouldn't get hung up on it if it's working.
sorry but when you did factory reset you did hold recessed button for 20/30 secs until lights flashed?