I might be running into a bug. Every time I try to use "update data" on a AGOL feature service from a FGDB the attachments don't come over. Attachments are enabled and editing is turned on. It runs and attribute data comes over and No errors or anything.
Noticed that the destination feature service size grows like the attachments are there.
Solved! Go to Solution.
https://doc.arcgis.com/en/arcgis-online/manage-data/manage-hosted-feature-layers.htm#APPEND
Adding or updating features does not add or update attachments on the hosted feature layer.
Not a bug - just a limitation of the easily accessible mechanism.
If you run the Append tool in ArcGIS Pro with the 'maintain attachments' option you should have better results.
https://pro.arcgis.com/en/pro-app/latest/tool-reference/data-management/append.htm
https://doc.arcgis.com/en/arcgis-online/manage-data/manage-hosted-feature-layers.htm#APPEND
Adding or updating features does not add or update attachments on the hosted feature layer.
Not a bug - just a limitation of the easily accessible mechanism.
If you run the Append tool in ArcGIS Pro with the 'maintain attachments' option you should have better results.
https://pro.arcgis.com/en/pro-app/latest/tool-reference/data-management/append.htm
Thanks for the info. This is unfortunate and a huge limitation.