Soundabout free/PRO setup only works first time

I have a Elephone S2 and I have a problem on my calls audio. I can't hear the other person or the sound is almost inexistent. Speaker works.

I downloaded soundabout free and after reading many posts I unchecked the option Wired Headset Detection and restarted. The first call I make the earpice audio works. Second time don't. I thought that might be because of the free version. Downloaded the PRO and same happens.

It possible to help me setting up soundabout when the Audio IN in earpiece is not working?

Thanks in advance

After you make the first call, what happens if you change the "Phone call audio" setting to Speaker and then back to "Let app decide" or "Earpiece"?

Does the second phone call work?