Thank you for the response.
I did the SMC reset a couple of times with no change in the connection.
A little background - the Mac is a 2020 MacBook Air 13" now running Big Sur V 11.1. It has 2 Thunderbolt ports.
The connection device was purchased through the Apple Store at the same time as the Mac.
The connection is to a JCPAL USB-C 9 port hub with type C adapter and then connected to a printer.
I connected the printer to an older Mac through USB "B" cable and it worked so it is not the printer.
I see that there are quite a few other reports on discussions.apple.com of very similar problems.
Also see kb.plugable.com which states "As of the 11/12/2020 release of Big Sur, multiple brands of Ethernet adapters..... are incompatible with macOS11 ...... as a result of Apple's implementation of DriverKit".