No audio is heard but RTP data is received

No, that won’t help. You may try by forcing Chrome67 handler in your mediasoup-client apps (just when the browser is Chrome of course) which uses PlanB and see if the problem does not happen. However it’s super hard to figure out where the issue may be.

BTW maybe you are trying to render remote audio before getUserMedia with audio succeed? If so some of your clients may run into the browser auto-play policy issues.