[Safari Mobile] Bad sound quality at the beginning of the meeting

Hello,

I implemented the jitsi meet solution on Ubuntu 18.04 server.

Conferences on devices (desktop) and phones (Android) work perfectly.

The problem only occurs in the Safari browser (Iphone), distorted sound is heard on the device.
After a few seconds, the sound quality of the phone is normal and good.

Jitsi configuration in files is default.

Please give me some suggestions.