For correct work of application:
1) In “Settings ⟶ Battery” turn OFF “STAMINA mode” and “Ultra STAMINA mode”.
Screenshots
2) In “Settings ⟶ Battery ⟶ ⋮ ⟶ Power-saving exceptions ⟶ Apps” turn ON Prof Reminder.
Sony Android 8
For correct work of application:
1) In “Settings ⟶ Battery” turn OFF “STAMINA mode” and “Ultra STAMINA mode”.
Screenshots
2) In “Settings ⟶ Battery ⟶ ⋮ ⟶ Power-saving exceptions ⟶ Apps” turn ON Prof Reminder.