“rasa inspect” fails to load JavaScript due to wrong MIME type

Rasa Pro CALM Developer Edition on Windows 10 with Python 3.9.13. When I run “rasa inspect” it starts local Rasa server (on http://0.0.0.0:5005) and opens a browser window at “http://localhost:5005/webhooks/inspector/inspect.html”; but the later fails to load JavaScript code because of wrong MIME type returned by the server for index_xyz.js.