Empty value does not pass Unique Values validation

Much like #2241699: Validator "unique value on multiple fields" pointing empty values as non unique which has been closed as fixed, the single value version of this rule does not work with empty values. Perhaps this is fixed for the multiple values option, but it still fails validation if you use the Unique Values option (not multiple) and considers the empty field not unique. There may be a way to do this with conditional validation or some setting on the rule, but I can't figure a way to make it work...creating new issue since I can't reopen the aforementioned ticket...