Okay, I think I understand this - the problem is on the hardware side. Phone automatically switches to other mic when in voice call, because the main microphone is broken or not fully functional (audio from main mic is non existent). On first voice recorder app when I change the source of sound to "voice communication (auto gain)" which switches source to loudspeaker mic, from there I can record the audio without any issue. I bet i did that before reinstalling app and it did not work the first time. Thanks for your help, I really appreciate it. I think this thread can be closed as solved.