It’s up to the drivers. On its own, most multi-channel devices will mount as stereo with the first two inputs being Left and Right. That’s so you don’t send it back.
Some devices mount Stereo in groups of two. Inputs 3 and 4 become Left and Right by themselves. —or— 5 and 6 become Left and Right.
Audacity has a multi-channel forum.
https://forum.audacityteam.org/t/multi-channel-recording-in-audacity/15644/1
See if Tascam has help forums or services.
It’s possible that the drivers affect Windows and you maybe able to go into the Windows Control Panels and set conditions there.
https://www.thewindowsclub.com/open-sound-settings-in-windows-10
——Do not download or install anything.——
Koz