I am running into an issue with the public forms integration with SharePoint. I get the below error whenever I am using a Lookup or Choice field that is configured as a dropdown. As a result of this no data is loaded from the SharePoint field.
Dear @MattG,
Lookup fields are fully supported, but there appears to be a bug if not the Title field is selected - thank you for the report! We'll try to release a fix as soon as possible!