QNAP core not seeing my USB connected Meridian Explorer [solved]

Since the latest update of QNAP firmware and the latest Roon program I find my TVS 471 no longer sees my Explorer on the USB socket or any of the other LAN network sockets.
Any clues on how to change this would be appreciated.
The normal established LAN network works fine.

Thanks, Chris

After a long investigation, this has been solved (mostly by PM with @chrislayeruk).

If you have the same issue on QNAP 4.3, please make sure you did not disable the multimedia functions in the QNAP Control Panel > General Settings:

Thanks to the the QNAP helpdesk and chris for his patience. This was also new for me, but you’ll never stop learning…