Hi,
I just created a new file geodatabase in Pro 3.5.4 (which I just updated this morning) and tried to export to it the selected features from a series of feature services hosted on ArcGIS Online. These features have attachments.
I exported point features and line features with attachments to my new GDB without incident. When I got to my two polygon layers, I got this error when I tried to export the selected features to the same GDB:
WARNING 001177: Attachments are not supported in this Geodatabase release. Only the feature class and its relationship class were exported to the GDB (not the attachments).
After deleting that layer and relationship class and checking (but not changing) my environment variables, I tried the export again and it succeeded, exporting the features, the relationship, and the attachments as expected.
I had the exact same experience with another set of features in a different polygon feature service. Got the error the first time, deleted the exported content, and then tried again and succeeded.
Anyone else having this experience?