One other suggestion - if you are using a value parameter of the string data type, it will interpret a quote character as literal quote in the Testing tab. The quotes must be omitted if your data does not actually contain quotes:
Yes. I’ve used the ‘enter’ key, saved, opened, and closed the named query. I’ve also copied the named query, then recreated the named query from scratch thinking somehow something internal may have been corrupted or something, no help.