Could my issue be related to this ?
Note that for me sound works when using Signal, Skype or any other app than the phone. Wiping the cache partition as suggested there but with no luck. Rebooting the phone in self mode does the same as well.
Otherwise maybe this could do the trick ? It’s a Xiaomi trick but looks like it has been applied to Samsung phones as well. (I’m not exactly comfortable with rooting the phone however)
PS : ticket moved there where it looks more relevant : https://gitlab.e.foundation/e/backlog/-/issues/1841