We are currently experiencing the same issue in Enterprise 10.9.1.
- Anonymous Access is enabled
- All the file types were precreated and added to the Content Library
- When viewing through the search bar, all the file types show and may be downloaded.
- When viewing through the Category Card (set by group), the map loads when an item is selected, the download button is visible, but get the "Some formats may not be available" instead of the list of file types that you see when signed in.
Uploading all of our data to ArcGIS Online is not an option due to Credits.