Multichannel recording through USB with WASAPI

I have a Zoom R16 which I have been using as an audio interface for Audacity with DirectSound as my interface. Recently I’ve been wanting to record with a friend, but DirectSound is limited to two channels. I want to connect two microphones, a keyboard and a guitar to the Zoom so I selected Windows WASAPI and set the number of channels to 4 (yes, I’m using the first four inputs on the Zoom). When I clicked the record button Audacity populated the required 4 channels and they all recorded - exactly one time! After that, anytime I select WASAPI I get an error code of 9997 (invalid sample rate). After scouring the internet and trying every solution offered (not that there were many) the problem persists. The Zoom / Audacity combination still works with the DirectSound interface but that doesn’t solve the problem of multi-track recording. I can’t for the life of me understand why it would work the first time and then give me an error going forward from there.

My Audacity version is 2.3.2 and my OS is Windows 10.

Any help available while I still have a few strands of hair left to pull out would be greatly appreciated.

Are you also using the Zoom as the playback device?
It’s possible that the Zoom may not support bidirectional audio data when recording 4 channels.