We are having same Issue with some FM photo attachments not sync'ing from offline map areas (attribute data syncs fine), no errors given in sync nothing seen in logs. We only noticed the attachment discrepancy while doing some QC on what was collected vs. synced. We are using ArcGIS Enterprise Portal 10.9.1 and FM 24.0.1 on a Galaxy Active 4 Pro. All my published layers from feature service have attachments enabled (and pop configured).
I don't see a pattern of why some photo attachments upload/sync and some do not? It does not happen consistently with the same map area, or same feature, and the # of photo attachments affected varies. I don't believe we are over the photo size limit threshold (each photo is less than 1MB) with the majority of points usually only have one photo, with a max of 4 photos.
Working online is not an option for this project, so we've had to use offline map areas. I have confirmed that the photos are in still tablet's SQL mobile geodatabase after a supposed successful sync to online map. So our tedious workflow prevent the loss of any photo associated with the data is to export each user's tablet mobile geodatabase file each night.
ESRI please figure out why your sync'ing process is spotty, this is a lot of post processing on a what was supposed to be a time saving workflow using fieldmaps. We would have gone with other technology if we had known the hiccups we would be facing in trying to make sure we keep all of our survey data.
