Hi Survey123 team.
My team is having issues with getting a copy of the data collected with Survey123 from ArcGIS Online. I have tried all options available (from Survey123, from the feature service, from the rest endpoint, from ArcGIS pro, etc. with no success. The maximum I can get is the main point layer without any attachments. This is the second time it happened to us in the last 3 months or so and last time it got fixed in 24h.
Update: It got fixed meanwhile I was typing this message. We were able to download the data from the rest endpoint but none of the other options work yet.
I'm glad you were able to get your data exported. It would be helpful if you could file a support ticket on this, focused on the export from ArcGIS Online - the Export button in Survey123 uses the same operation as the Item Details page in ArcGIS Online.