Solved! Microphone has developed slight echo

[hedgehog90]

I'm using an Avantree Bluetooth headset with a mic.
A month ago my mic worked fine, but I started noticing a slight echo in everything I record, recently.
It's quite subtle, it's not like a big booming echo.
I've tried just about everything I can think of to try and fix it...
I've tried disabling mic enhancements, fiddling with the recording device properties, uninstalling and reinstalling audio drivers...

Something a strange that I noticed... in my recording devices, I have 2 recording devices - my Avantree headset and Realtek HD Audio.
Mysteriously, the Avantree headset doesn't show any activity, but Realtek HD Audio does. But when I view my available recording devices in another progam like Audacity or OBS, it just shows the Avantree mic, and that's where I'm noticing echo.
Very odd.

 

[hedgehog90]

I wrote the above post on someone else's behalf.
Turns out he has a physical echo control on his headphones that he was, until today, completely unaware of.