Syncthing is always terminated after some time. Have Android 7 on my mobile phone and Syncthing runs with foreground priority. I am in the Beta program
I think syncthing is not automatically started after Wlan is recognized.If it is so adjusted the synchronization can only be done over Wlan.
Yes, all the items in the FAQ were set. Sync was just finished again. There was also no WLAN interruption. It makes the impression as if Android 7 is to blame for the interruption. On the phone of my wife runs Android 6 and syncing is not finished.