In ArcGIS Pro 2.7.x, only feature layers appears on ArcGIS Living Atlas from the Portal tab in the Catalog pane, when the active portal is ArcGIS Enterprise.
This issue was resolved in ArcGIS Pro 3.0.
Before ArcGIS Pro 3.0, the default sorting option used when accessing all portal items was Date Modified, items would be listed from newest to oldest. When this sort option is used with Living Atlas, content and public content available from ArcGIS Online and ArcGIS Enterprise in the top 100 results often include only feature layers since these are the items that are most frequently published or republished when the data is updated. With this sort option, when Find more items is clicked, at the bottom of the contents list, the next batch of portal items displayed contains other types of web layers and web maps that were recently updated.
In ArcGIS Pro 3.0, the default sort is used when listing ArcGIS Living Atlas content from ArcGIS Online and ArcGIS Enterprise.
In ArcGIS Pro 3.0, portal items uses the Relevance sort option by default, which corresponds with the same default values used when the same content is accessed in the portal using a web browser. In older versions of ArcGIS Pro, the preferred workaround is to change the sort option from Date Modified to Relevance.
解决办法
Upgrade ArcGIS Pro 2.7.x to ArcGIS Pro 2.9.x.
Set the active portal to ArcGIS Online in ArcGIS Pro 2.7.x.