I should note that the ternaries used in this are part of the troubleshooting...they were not used originally.
The only hint of a possibility is that I have so far only been able to make it fail when the tag-text begins with a numeric character. But even this does not ALWAYS fail.
It appears to see it as a non-listed item so therefore uses the text entered as the value. The only reason I can think of is that it is only looking in a certain number of items
The max-items only limits the number of items that is shown in the autocomplete droplist.
I'm trying to reproduce the issue but currently have no success with that. If there is more information when it fails then perhaps I could pinpoint the problem, currently I have no idea where to search.
@patrick This is happening to me as well. It appears to happen when there is a space at the beginning or end of the value for the tag-text runtime element.
@bpj and @mebeingken, could you see if that is the cause for you?
As an example, the First Name has a space at the end. If I remove it, then the form submits successfully. If I add it back it gets the error. I've validated with multiple records and this happened consistently.