I stumbled upon what I believe is a bug when changing the cardinality of a runtime data source from many to one.
After adding a runtime data source with cardinality many, I built my Persist action for the runtime source and set the Selection to ‘Selected object(s)’. After seeing that my runtime data source should rather have cardinality one, I went into the App Data and changed it.
When I tried to persist my data (where one of the object properties had a value linked to another data source) it wouldn’t show correctly in my UI. When checking the data source in the developer tool I noticed that the value I was trying to view in the UI was a “random” id (i.e., ‘64134323c7f5111c777330fb’). Trying to locate any object with this id gave me zero results.
Moving back to the persist action I noticed that the persist action still had the description text ‘Persist all selected data in to server’ but the Selection option was no longer available for change.
Removing the persist action (that was set up when the data source had cardinality many) and adding a new persist action changed the description text to ‘Persist all data in to server’ and the UI (as well as the data source in the developer tool) now showed the correct values.