It’s not unusual for a stereo system to insist on being stereo, but it’s dead easy in Audacity to split them in two for production. Drop-down menu on the left > Split to mono. In the case of a single microphone, just [X] delete the track you don’t want.
They laughed at me when I bought a mono USB microphone system …
Some systems will mount your system as a single microphone in Audacity preferences > Devices > Mono.
Does Device Toolbar see these two mics as two separate devices? I would guess not if they are both connnected to the same USB device.
What do you want, to record two mono tracks? Try Tracks > Add New > Mono Track, Tracks > Add New > Mono Track again, SHIFT + UP arrow or CTRL + A to select both tracks, then SHIFT-click the Record button to Append-Record into those tracks. This works for some people.