Уже неделю телефон находится в режиме «бесшумный».

Hi.

Check this link and see if it helps you:

https://discussions.apple.com/thread/250624956

Translation:

Good afternoon.

For a week now the phone has been in silent mode.

Without sound notification messages come, the speakerphone does not turn on.

Despite the fact that the "volume" in maximum mode.

This happens regularly. You have to overload the phone or close open pages.

This has never happened before.