According to the system characteristics in Android 6.0 and newer, your mobile phone will change to doze mode automatically if you leave it unplugged and stationary for a period of time which leads to the issue of reminders being delayed in TickTick. Therefore, to switch on Alert Mode may be helpful in this case, you can enable it through:
- Tap “Settings”
- Tap “Reminder” then choose “Reminder Instruction” at the bottom
- Tap “Android 6.0 and newer”
- Enable “Alert Mode”
Note: There’ll be an “Alert” icon appears in the status bar when Alert Mode enabled.
Meanwhile, please double check if you’ve installed any security applications. Some of them might have blocked notifications from TickTick.
Please make sure TickTick has the notification permission on your phone. If you can’t find TickTick in System Notification Settings, you may create a task with a reminder to trigger the notification permission again.