I am currently having an issue using webhooks with Survey123, where the payload does not appear to be sent at submission time. I am using an existing hosted feature service to create and publish my surveys, each survey is pointed at a separate related table within the feature service (i.e.1 feature class related to 3 different tables using 3 relationship classes at the database level; nothing nested, all tier 1 relationships). I am able to create the surveys without issue, publish them with no problem, and add records to related tables using Survey123, again without any trouble. I can see the data on the Survey123 website as it gets submitted, both in the table on the data tab, and in the action tab that comes up when you select the record in the table. However, the webhooks do not appear to ever be triggered when the survey is submitted, which is evidenced by not seeing any sort of failure or success messages within Integromat or Microsoft Flow.
In contrast to the previous workflow, I have another hosted feature service that only contains a single related table. When I create/publish this survey in the exact same way as outlined above I am able to make use of the webhook without any issue. To be clear, all of the feature services mentioned in this post are hosted on ArcGIS Online, use non-versioned data, rely on GlobalIDs for the primary and foreign keys, have the foreign key's GUID fields added to the surveys with the XLSForm's field type set to esriFieldTypeGUID, and have the form_id set to the name of the corresponding related table. The only difference across both implementations, is that one feature service has multiple related tables, while the one that functions contains a single related table.
It is vitally important to have the previously described workflow (i.e. relationships like FS1 > FSRelatedTable1, FS1 > FSRelatedTable2, FS1 > FSRelatedTable3), since each of the three survey types record very different data, contain a varying quantity of fields, and require that the payload data be converted into 3 very different PDFs, which then get emailed as attachments within our Integromat workflow. I have contemplated workarounds, but I am not interested in having multiple feature services for each type of survey, since the data being collected, while quite different at the table level, is very much aligned at the feature class level.
This part of the project is the last piece of the puzzle (all other systems are a go), but without a functional webhooks component the whole project essentially collapses. Please help!