@Stephanie77
Check account dashboard to see that you have a number for activated sim and also a current Smarty plan.
Carry out a Coverage Check (if you didn't before joining) and also a Network Status check to look for any local mast problem.
If it carries on, have a web chat with Smarty Support team - https://smarty.co.uk/contact
When you connect to wifi, you are using the broadband connection in the property and so that's why you have a connection.
