Voicemessage not playing through earpiece

• /e/ version: IMG-e-0.9-p-2020070161107-dev-FP3
• Device model: FP3
• When it started to occur: Fresh install
• Reproducible with the last /e/ version: Yes
• Reproducible with LineageOS: N/A

Summary

Voicemessage is not played-back in WhatsApp via earpiece. Was already an issue with stock rom but I was at least able to play it partly (similar to this bug report). After fresh install of /e/, it now refuses playback completely. Speaker playback works normally.

• The device is unusable
• The bug is the source of a data loss or a big waste of time
• The bug concerns a third-party application
• The bug concerns security
• The bug concerns privacy

The problem

Steps to reproduce

1. Listen to voicemessage in WhatsApp.

What is the current behavior?

1. Does not play anything. Playback (even speaker) completey blocked for about 5sec.

What is the expected correct behavior?

1. Voicemessage should play through earpiece.