If you suffer from poor or no mobile phone signal at home or work there may be another solution. You can try Wi-Fi calling if your phone has this feature, and your internet is strong enough. There are loads of how to’s online specific to your phone as to how to set this up, if you have this feature. Once set up this means that your phone will use your Wi-Fi automatically when out of signal. This is good when it works, but I found that sometimes a tiny bit of signal would appear, which took me out of Wi- Fi calling and then the call would frequently drop.
It took me ages to figure out but in the end it’s simple. Put your phone into airplane mode. Everything stops. Then restart your Wi-Fi only. The phone will then just use Wi-Fi calling. You can also restart your Bluetooth if needed.
The only downside is you can’t get normal texts, but I use Whatsapp most of the time so it’s fine.
I hope this helps 🙂