Overview: Attempting to run a fuzzy search for images that were favorited by a user results in no results.
Affected areas: Only the posts are affected.
Expected Behavior: I should be able to get the favorites of multiple users.
Actual Behavior: No results if a ~fav:foo is run.
Reproducability: Absolutely.
How to replicate: Run a search with ~fav:foo ~fav:bar (Or even just either of them separately) and you'll get no results. You'll have to run fav:foo and fav:bar separately.

Unfortunately this is a limitation of the parser, and thus, expected behavior. Metatags can only occur once per query, and the fuzzy(OR) search for them doesn't have meaning when there can only be one item.

I would suggest filing this as a feature request and expanding the scope of it so to allowing multiple of a given metatag in a query. This would open up searching like this as a possibility.