Just a suggestion.

Both Apple & Android phones will allow selecting from available roaming carriers your phone sees at your location. Perhaps try and switch off Automatically Select Network for Android, or Network Selection for Apple and choose another local carrier from the available list. Perhaps the one your companion is roaming on. You can work your way down the list in a few minutes. I always toggle Airplane Mode between choices to speed up the process. I only mention this, since your description didn't include this advice from your contact with support.