This is becoming a big issue, and Esri support has not been responsive since I placed a support ticket in last week. When we updated our Survey123 apps (latest version of iOS on iPads that are less than 1 year old), attachments are not getting loaded into the form, which in turn, means they don't get sent to the feature service when you submit the survey. We have repeated this issue on 4 different iPads.
These attachment fields are in a repeat, but I don't know why that would contribute to the problem.
I've attached a video that demonstrates the issue we are having. When you see an attachment field with no thumbnail image, those will not send an attachment when you submit the survey. To fix this, we have to add those attachments either in collector, or in a web app, which is causing serious workflow issues.
Any suggestions would be greatly appreciated.