Hey there ashley_handley,
It's possible your cellular data might have been disabled for these apps. To check cellular data settings, go to Settings > Cellular, then scroll to see your apps. If the app is disabled, you can tap to enable it. Go ahead and test to see if this persists after enabling.
If this does continue, you can isolate possible app related issues by using the steps below:
Close and reopen the app
Force the app to close. Then open the app to see if it works as expected.
Restart your device
Restart your iPhone or restart your iPad. Then open the app to see if it works as expected.
Check for updates
To see if updates are available for the app, open the App Store, tap your profile icon, then scroll down to see if updates are available. If updates aren't available for the app, update the software on your iPhone or iPad.
Delete the app, then redownload it
Delete the app. When you do this, you might lose data that was stored in the app. Then redownload the app. Then check to see if the problem with the app is fixed.
If an app on your iPhone or iPad stops responding, closes unexpectedly, or won’t open - Apple Support
Finally, should this continue and you're still unable to use cellular data with the apps, reach out to you carrier so they can look into things from their end.
Take care!