Extra info: I'm using the Audio Player plug in.
Warnings I get from Facebook debugger:
Meta with name instead of property:
The meta tag on the page was specified with name 'author', which matches a configured property of this object type. It will be ignored unless specified with the meta property attribute instead of the meta name attribute.
Objects of this type do not allow properties named 'og:audio:title'.
Parser Mismatched Metadata:
The parser's result for this metadata did not match the input metadata. Likely, this was caused by the data being ordered in an unexpected way, multiple values being given for a property only expecting a single value, or property values for a given property being mismatched.
Here are the input properties that were not seen in the parsed result: 'og:audio:title'