I'm having a bizarre issue with the Change Content Type control.
I have a library with multiple Content Types. When I use the OOTB SharePoint form I have no issue.
The minute I try to add a nintex form to the default content type and apply it, I get the following problem:
-Upload a doc, try to change the content type from the drop down. Fill out all required metadata. Click Save.
-Content Type change is not applied, still says it's the default content type (top one in the list).
I have run dozens of scenarios and this always breaks when I try to add a simple nintex form, even if it's the default layout without any changes except adding the content type selector control.