In some tools like "Resources" or "Tests & Quizzes", seems like CK Editor Audio recorder is not working properly.
For example, in Resources, if you create a new HTML Page and you click on "Record Audio Clip" button:
You will can record the audio with no errors. However, the audio HTML5 auto-generated tag inserted in the CK Editor textarea doesn't includes the "src" attribute. Also its MIME Type is incorrect:
In other tools like "Assignments" this is not happening, as you can see: