Audience with AD Group containing external users get access error

Hi Community,

I have an issue with an App Audience.  We have an AD Group which contains external users.  When I grant them access to an Audience on an App the users in the AD group get the messaage "You don't have access to the contentt".  If I grant one of the exteral users access to the App Audience directly they can access the App with no issues.

I have checked the settings on the group and they are fine.  This AD Group with external users can access other items in our network such as SharePoint pages and lists.

Is there another setting we need to look at to grant the AD Group access to the Audience?

Thank

DKHughes55