I am not using a Patch function but I am receiving this error on two of my forms:
Network error when using Patch function: The requested operation is invalid.
Here's a screenshot of the form:

I'm not sure where else I can look to resolve this issue. My Datasource is a SharePoint list. The Return to card is a People/Group column and the other dropdowns are all SharePoint text columns changed to dropdowns by applying Allows Values.