Why are my iPhone notifications arriving without sound?

Hello. A few days ago, I stopped receiving notifications on my iPhone with sound, and the screen lights up (the watch vibrates as usual). If I accept the Apple Watch, notifications come as usual with sound, vibration, and the screen lights up. Nothing has changed in the settings, but when everything broke, I went into the settings, there all notifications are turned on, both on the phone and on the watch. I tried to tear apart a couple of watches and the phone, completely, this also did not help (I set it up as a new watch). I also installed the latest OS updates on both the watch and the phone, but after the sound disappeared, this also did not help. And I also reset the settings on the phone itself, it also did not help. Please help solve this problem

[Re-Titled by Moderator]