MIUI · HyperOS
MIUI and HyperOS are especially aggressive at putting third-party apps to sleep: without auto-start and with battery saver on, call notifications don't arrive and callback reminders fire late. The five settings below fix this for good. Item names may vary slightly between MIUI/HyperOS versions.
Open Settings → Apps → Manage apps → ProZvonki and turn on Autostart. Without it the app won't start after a reboot and gets killed when memory is cleared. The same auto-start list also lives in the Security app → Permissions → Autostart.
In the app card (Settings → Apps → ProZvonki) open Battery saver and choose No restrictions. This is the key item: MIUI battery optimization is what most often kills the app in the background.
In the same app card open Other permissions and enable: Show on lock screen, Display pop-up windows (including while running in background) and Start in background. These let the incoming call screen appear over a locked phone.
Open the Recents menu, find the ProZvonki card, swipe it down (or long-press) and tap the lock icon. A locked card won't be closed by the "clear all" button.
For exact reminders open Settings → Apps → Special app access → Alarms & reminders and enable ProZvonki (Android 12+). Make sure notifications for the app are on (Android 13+).
Tip: if calls matter or you use dual SIM, set ProZvonki as your default phone app: Settings → Apps → Default apps → Phone app.
FAQ
Two ways: Settings → Apps → ProZvonki → Autostart, or the Security app → Permissions → Autostart. Turn on the toggle next to ProZvonki.
That means Autostart is off (step 1) — without it the app doesn't start after the phone powers on. Also check that Battery saver is set to No restrictions.
Enable "Show on lock screen" and "Display pop-up windows" under Other permissions (step 3). On HyperOS they may be named slightly differently, but the meaning is the same.
