Debugging current Application (Android/Java)

Rough description of the app functions:

Function:
We have an app that synchronizes videos from our web server (download to local storage) and plays them in different tariffs. Currently, the server also provides playback times of the tariffs. The query is made each time the app is started and then every 60 minutes.
Tariff 1: (All) 24/7
Tariff 2: (Weekend) Fr 10pm - Sun 6am & Sat 10pm - Sun 6am
Tariff 3: (Weekday) always except Tariff 2 (Weekend)

Next Function:
The display brightness is controlled by the app. To do this, the app asks the web server at the start of the app and every 30 minutes what percentage of the brightness should be set to.
Due to the poor quality of the mobile network, it occasionally happens that the app starts without or with a slow (Edge/2G) Internet connection. Therefore, neither the tariffs, new videos nor the brightness can be queried. In this case, the app plays the last saved parameters.
If an internet connection is established later, the app will immediately query the current parameters of the server.

Error description:
Because we have many holes in our German mobile network with poor or no network coverage, the connection is repeatedly interrupted and the app reconnects to the mobile network. In this case the current playlist is aborted and played from the beginning.
This sometimes happens several times in a row.
It also happens sporadically that the app does not send a query at all.
For us it is important that all queries are executed reliably in the background and that the playlist is only affected in case of a tariff change. (No termination of the videos)

Order:

The errors should be corrected.
AND
The brightness should no longer be queried via the web server.
Instead, a fixed table of values in the app should be used to compare it with the local time of the device (display) and adjust the brightness accordingly.
At night = 1% / during the day 100%

Please make us an offer for these changes.