After the last update the calls and messages are working but not the audio. It's been working fine for 7 years now It's not. Samsung what is your solution it seems as you have a lot of complaints on this issue.
Sounds like a half story. Are you referring to Bluetooth? More information is necessary. Since you say it's been working 7 years and the S21 has been out for less than 2 years I assume the devices you connect to has been working for 7 years in which case it probably has an older Bluetooth version.
If you want a meaningful answer please give less vague information.