I have no idea why T-mobile would tell your device to turn off "cellular data" if WiFi was available. I don't have a T-mobile account, but I don't see that behavior with Verizon or AT&T. You should be able to leave both WiFi and cellular data enabled at the same time, no matter where you are. As I pointed out in my previous post, your device can be set so that it
requires you to use WiFi (rather than cellular) data to install App Store programs.
Unless you have purchased the feature from your cellular phone provider, you might not be able to activate the
Personal Hotspot feature in
Settings. This depends on your cellular plan.
If you actually have the Fastmail app installed, you can see some details by following these steps:
- Open the Settings standard iOS app (which looks like concentric grey gears).
- At the top level of Settings, scroll way down until you see the alphabetical list of apps you have installed from the app store. Look for Fastmail and open that entry.
- You should see the choices I described in my last post. You should also see the version of the app you have currently installed. The latest version is 2.15.2116.
You can install the Fastmail app on your iOS device (if you have an internet connection) by opening a browser on the device and going to:
https://apps.apple.com/us/app/fastma...ts/id931370077
If you have an older Fastmail app already installed, this will just overwrite your old app with the new one.
Bill