The value of the HTML attribute hreflang must be a valid BCP 47 language tag.
The HTML validation fails because of invalid language codes: https://validator.w3.org/nu/?doc=https%3A%2F%2Fwww.wikidata.org%2Fw%2Findex.php%3Ftitle%3DQ5296%26diff%3D807351493%26oldid%3D272854