@td47 After the firmware update, only the 5Ghz network had a problem with using the hyphen. The 2Ghz network continued to function well even with a hyphen in the network name.
I really believe that it is a bug in the firmware version, however, it is possible to continue using the device normally just by making this change to the SSID of the 5Ghz network.
An easy problem to solve but difficult to discover .....