Hi,
We're using Campaign Classic, and have been working through the integration to pull segments from AAM. We've completed setup by following this guide and have had Adobe set up the necessary provisions: https://helpx.adobe.com/marketing-cloud/how-to/aam-campaign.html.
When we reach step 10 in the guide above, and click "Select a shared audiences", a new window opens as expected; however, that window never loads any of the Shared Audiences we have created from AAM, please see screenshot below:

It never loads, and we're unable to figure out why this is occurring.
The user attempting to do this is using an Adobe ID with the following permissions:
Admin in all these areas:
- Adobe Campaign,
- Audience Manager,
- Audience Library,
- the Custom Audience Manager Group,
- and also in the Adobe Campaign Experience Cloud profile,
- For Adobe Analytics full admin access in the cloud as well
Any recommendations would be appreciated, thank you.