Whatsapp vocal messages always in "speaker" mode - Fairphone 3

Hi all :slight_smile:
I have an issue with Whatsapp vocal messages on my Fairphone 3.
All the time that I want to listen to a vocal message privately (so placing the phone over my ear), the audio goes back to “speaker mode” after couple of seconds. It is very annoying as basically I cannot listen to vocal messages
privately unless I have headphones.
Anyone with the same issue and any ideas on how to fix it?

Thanks a lot in advance
Roberta