What can be my APP works correctly on Android 5 and does not work properly ne Android 7 transferring data to a Webservice?

My APP transfers by wire connection through a URL, informs it to a Webservice, I test it on a cell phone with Android 5 and transfers the data correctly, when I run it on a cell phone with Andorid 7 it does not transfer.

My APP is developed in Android Studio, the cell phone that does not work is:

Samsung Galaxy A5 with Android 7.0