I believe this is a bug caused by the code responsible for checking that a domain ends in a public suffix expecting the domain to be encoded in unicode, while it’s currently being provided as punycode.
I’ve filed an issue here as well as a potential fix, but it’ll probably take at least until Thursday or Friday for this to be deployed (assuming the fix is adequate and will be reviewed and merged in time). (This is a guesstimate based on the typical release schedule, nothing more. 
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