Hi , I am trying to get rid of the internet connection via landline using an only data Smarty sim card (unlimited), but I have issues with international WiFi calls via an app called Rebtel. In practice the app uses the wifi to ring a phone abroad. Everything is fine for few minutes but then suddenly the line drops even though the call is still on, and it happens all the time. There are no issues if I use the conventional internet line. Any Idea?
By the way I used an industrial grade router and a 5G mobile phone....no difference
