So I recently purchased a USB Audio Adapter, so that I can use my in ear headphones, SoundMagic E10S (https://www.whathifi.com/soundmagic/e10s/review). These connect to the adapter via the headphones own splitter cable that came with the headphones. The headphones are TRRS, and the splitter takes the in and out to TRS.
The device is connected and detected by Windows 10 fine. I then use the device in MS Teams, and I can hear people, but they cannot hear me.
The diagnose the issue, I have used Audacity to record me speaking, and I can see the the input is only received on one channel, the right side.
Just to check the headphones, I have run the same test with the headphones plugged into the 3.5mm jack on my laptop, and recorded via Audacity. Mic input signal is recorded on both channels. I have no way to test the splitter cable that is shipped with the headphones.
Any ideas as to why the mic input is not split across both channels?