No notification when task is scheduled 2 hours or longer in the future (possibly less than 2 hours)

[Tokkes257]

:ghost: Brief Description

After some time, I don't receive notifications anymore from the app. When i have a task scheduled within half an hour or so, i get a notification, but when it is scheduled in 2 hours and i don't open the app anymore, I don't get the notification for the task

:pancakes: Action version

I'm using the app downloaded from f-droid. I'm using version 21.0

Steps To Reproduce

Steps to reproduce the behavior:

1. I make a task and schedule it (for example 2 hours in the future)
2. I close SupProd and don't open it before the scheduled time for the task
3. When I should get a notification of the task, I don't receive it until I reopen the app

:police_car: Expected behavior

Getting a notification for a scheduled task, even though it is more than 2 hours in the future and I don't open SupProd in the meantime

:heavy_plus_sign: Additional context

I have disabled battery optimization I have locked the app in the recent list I'm using a OnePlus 5T

[johannesjo]

Thanks for opening this up! Help (mainly PRs) with the issue would be welcome!