Hi @Robyn Broening ,
Welcome to our forum!
Are you referring to the issue shown in the image below?
If so, as i know, the issue will occur when you use New Outlook. For the "Contact Lists" feature, it is not available in New Outlook for Mac. More information: The new Outlook for Mac.
As a workaround, it's suggested that you could revert to the Legacy Outlook to use this function (via Help>Revert to the Legacy Outlook).
Hope the above help!
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