We have an Experience Builder App with a Custom Widget which is calling a GP Tool to do an editing operation (copies a feature from one layer to another) The POST call that gets submitted has a feature collection as a parameter, and it sends (one or more) POLYGON features in the collection with a proper Object ID, and attributes and geometry. We've added messages in the published GP Tool to see what it receives, and it is getting a feature collection of POINT features with one or more features with IDs in the set [1,2,3....] and no attributes beyond the incorrect object ID and geometry.
For context, this is a forestry app that is creating silviculture plans from harvested blocks.