Certain app not working on mobile data but working on WIFI. How can I get it to work on mobile data?

[AC Question]

certain app not working on mobile data but working on WIFI

I use an APP to remote control a electrical power outlet ( on, off, scheduled on & off)

This app works correctly on my Samsung S5 on both WIFI and Mobile Data.
However the same app works only when on WIFI and can't connect over Mobile Data.
The only difference I see is that the Mobile Data carrier is different.
Swisscom network = OK
Sunrise network = NOT OK
The app uses the "normal" htpps port 443
The app just hangs trying to connect to the server then times out.
I was wondering how to debug this

 

[NerdgrlApps]

I guess you can make at least 2 things:

1. Try to check if this connection (via mobile data) works in other apps, i.e. in simple web-browser.

2. You will need Android Debug Bridge (ADB) to collect logs from your device. Plug your phone into PC via USB cable, allow USB debugging in Developer settings, then run "adb logcat > log.txt" in the command line and run your app. It will collect all logs from your device and save them into log.txt file, where you can possibly find logs related to your issue.