Hello @Simonwildman254 it usually fixes most errors yes. Restart your phone in between deleting the app and re-installing to clear any temporary files that could bug it up again.
If the app still does not work are you bake to register the number by logging in to MYEE online through a browser? When logged in if you navigate to MYEE>account settings it should take you straight to the add number page. 🙂