Hi Lorna and welcome to the business forums.
Thanks for letting us know about the issue you're having on Call Forwarding, No Answer. Do you by chance have any other forwarding rules set up such as Call Forwarding, Busy?
Here's a link on other Call Forwarding features: https://business.comcast.com/help-and-support/voice/manage-call-forwarding-voiceedge-select/. This also provides what the feature looks like in the business portal as well as the corresponding star code. It's a pretty useful link when you need to set any forwarding up.
If the line were busy it would forward without ringing as the line would be in use. Since you state that the line was not in use at the time I would like to look further into the services. Would you please provide the name, address and phone number on the account for me?