I have a survey intended for use by the general public that, amongst other things, allows images to be taken/attached. The public users access the survey directly in the Survey123 app by clicking on a link sent to them (i.e. they don't log in to ArcGIS Online with an account username and password). Due to the nature of the survey I have modified the settings on the survey's Feature Service to that shown below - I want anyone to be able to add data to the survey but for no one outside my organisation's administrators to have access to it once submitted.
Everything works fine until records are submitted with an image attached. This gives a code 400 error and says the record has not been submitted (although I think the non-image bit of the record actually has). If a record is submitted without an image it goes through fine.
If I log into my ArcGIS Online account and submit a record with an attached image the record is submitted without error (although I can't seem to preview any of the data from the survey when I log into the Survey123 website and look on the 'Data' tab for that survey).
Is this a bug or something I'm doing wrong with the permissions? I've tested this on both an Android tablet and an iPhone and I get the same issue.
Many thanks in advance.