applications – AudioMixer and AudioFlinger Recoding from Stereo to Mono

I have tried to record from an Android 9 device audio with tinyCAP in the format

48kHZ,STEREO,16 bit

The waveforms differ quite a lot, however when I call from Java APP record

The waveforms are the same.

Possible places to happen AudioMixer and AudioFlinger.

I checked the Mono Sound on the Accessibility settings and it was greyed out, do you know any place where this is defined in code. I think that’s causing for both channels to be the same.

If it’s AudioMixer, where would you suggest I look for?