Software problem earpiece speaker. no audio on calls

I recently bought a Fairphone 4. I just discovered an audio problem while calling.
I did this test, https://support.fairphone.com/hc/en-us/articles/115001041206 & hardware seems fine. But when I call I don’t hear anything from the earpiece speaker. When I put it on loudspeaker I can hear the other end of the line. Also in safe mode, the problem keeps persisting. Any help will be highly appreciated!