Has the WTO adjudicated any disputes in which unofficial trade barriers were alleged?

In a recent case against China, the EU alleges that various "errors" have started to pop up in the processing Lithuanian goods by the Chinese customs. However, no explicit Chinese laws or regulations hindering Lithuanian goods have been mentioned in the EU complaint.

Has there been any remotely similar WTO case, in which alleged but not officially acknowledged trade barriers were the subject of the dispute? Were any such cases won by the complainant?