Can you start with a soft reboot by turning your phone Off and On @andybeach
Please also look in any relevant sound settings in the phone if you haven't already done so.
May I assume the sound is working on normal speed video's ?
And on calls etc.
Daily Driver > Samsung Galaxy s²² Ultra 256Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help.