Hello,
We are having problems when using Survey123 in browser and submitting a photo. Photo does not get saved to the feature service.
If we use the app, no issues, photo gets saved and can be viewed.
The survey in Portal, version 10.8.1. Googling did not show any similar errors or bugs. The survey is publicly share for simplicity of use, so browser might be preferred option (as no need to download the app).
Image below is the data view of the feature service that survey uses. Some attachments are no there (shows as zero), however survey has photo as a compulsory field.

