Unable to remove a read-only content type from a list or library

Consider this scenario:

- A Content Hub is in use and content types are published to a subscriber site.

- I add the subscribed Content Type to a library.  Works fine.

- Under Settings for the library, I click the newly added content type.  I choose the "Delete" option.  I receive the following error:

The content type "MyContentType" at  "/MySubsite/MyLibrary" is read only.

I am unable to remove the content type from the library (there are no files in the library).  I can delete the entire library and start over, but how can we remove read-only content types from a library after they are applied?

Thanks for you help!