What to do if automatic Do Not Disturb rules don't work in Android 10?

Question

Android

Android 10, Alcatel 1B 5002H smartphone (with latest updates).
When setting automatic Do Not Disturb rules, they do not work, that is, they do not turn on according to a schedule and do not turn off. Sometimes somehow it turns out to force this mode to turn on (reboot, do not turn off the screen, etc.), but it never turns off automatically. And this mode does not turn off if you turn it on manually for a specified number of hours.
"Intelligent power optimization" is disabled, in the "Battery saver" menu item, all Android services are switched to the "does not save battery" mode.
Tell me how to cure or where to look?