I have issue with custom form for document libraries on SharePoint.
This problem appears when I have two content types enabled: "Document" and "Document Set". If I customize form with Power Apps and publish it, then each time when I want to create a new "Document Set" my custom form is opened but I'm not able create a new Document Set. First of all, Such content type is not visible in "content type" field. Secondly, when I try to save item (create a new one, I receive error: "The requested operation is invalid. Server Response: To add an item to a document library, use SPFileCollection.Add()..."