This is a follow up to #1549, where since was added. I realized that "since" only works when it is the single attribute to an Issue query. However, when there is another attribute like "status", all issues are returned.

Example: this API query and that API query should return the same number of results, but they do not.

This issue has a performance impact on our tool maintaining a cache of Pagure issues. It periodically updates the cache and now it needs to always process all of the repo issues, instead of processing just the new ones.