I have the same problem with my R-41PM. I run Mac OS 10.15.3 Catalina.
They have been working for a a couple of years but suddenly stopped a while ago.
Sometimes they showed up as "Bravo-X USB Audio", instead of Klipsch-xxxx but they didn't work.
I got them to work by connecting them straight to a MacBook Pro USB port. (Not always, though.)
I'll try a different cable or USB Hub when I can.
This is what they look like in System Information:
Bravo-X USB Audio:
Product ID: 0x9023
Vendor ID: 0x262a
Version: 0.01
Speed: Up to 12 Mb/s
Manufacturer: SAVITECH
Location ID: 0x14100000 / 26
Current Available (mA): 500
Current Required (mA): 100
Extra Operating Current (mA): 0
