Hi Justin,
Here's what Esri had to say:
"I was able to reproduce the issue and had been trying to find out a reasonable explanation for the behaviour. It seems like, the Collector for ArcGIS doesn't right away populate the default subtype value in the field. Instead, it prompts to select the type value first and then lets presents you the related table edit form for editing other field values.
Now, the behaviour is different from what we observe in ArcMap when creating a related record. I had a conversation with Dev in this regards and they have termed this to be an expected behaviour. According to them, the related table would present all the possible types as defined on the related table REST endpoint and would prompt the client to choose the type first.
I understand that although this has been considered as an expected behaviour, I understand that it might prove to be a snag in the project that you are working on. The user experience and the functionality should be same across all the platforms. This can however be portrayed as an enhancement to the app. I can go ahead and submit an enhancement on this specific behaviour. Would really appreciate if you could send over the following details in support of the request:
- Business justification.
- No. of people affected.
I would include this in the enhancement request to present a concrete use case. Let me know if you have any questions or concerns. We can even schedule a phone call as per your convenience."
I work in a large organization and have a large user group that are requesting this functionality so will make an enhancement request to Esri. In my world, enhancements are usually at the bottom of the "to-do" list and bug fixes get the priority, so who knows if this enhancement will ever be incorporated into Collector. I'm keeping my fingers crossed, though!