macbook pro – How do I troubleshoot screen capture utilities only capturing one side of audio?

I use screen capture utilities like Movavi and Snagit on my MacBook Pro 2019 (Big Sur) to record software demos. When using a headset or any other microphone connected to a USB port, the recorded audio is in stereo.

When I use any external audio interface (PreSonus Studio 24C or Behringer U-Phoria UM2) as the captured audio source, I only get one side (the left side) of the audio. Using either interface with an application that doesn’t capture the screen in any way works perfectly, clear audio from both sides.

I’m certain that the audio interfaces are working properly. For instance, I can record my voice just fine using Vector 3 (or any other audio recorder) and the audio interface, and it’s clear stereo.

I need to use an audio interface because the mic I need to make a good recording needs an interface in order to work with my MacBook Pro. I haven’t had a lot of luck troubleshooting this, even through contacting support from Movavi and Snagit. I’m trying my best to go through all possible system settings and configuration tweaks that I can – is this a common problem with screen capture scenarios? I was about to chalk it up to a third-party bug, but this seems to persist no matter what utility I use, yet the audio interfaces work perfectly fine with any other software that isn’t doing a screen recording and I’m a little baffled as to why.