Power Platform Community Forum Thread Details

Evening all, I have a problem for which I'd like some help (and if possible an explanation of the behaviour). Here's the issue:

I have one SharePoint list which acts as a master list of projects (it uses the Title column and this column has three records, 'Project X', 'Project Y' and 'Project Z').
I have a second list where I have a choice column called 'Project' and I want to use these values. I have customized the form with an on start action to write a collection to get the project names. I have replaced the original value in the datacard to the name of the collection. These values appear in the datacard.
When I go back to SharePoint and try and add a new record, the values is not saved.

I have tested the above and when I write to a single line of text column, it works - so the questions are: