Currently, the star rating review filters in our system are treated to be "AND" statements instead of "OR" to help narrow down review searches more easily.
So, if you have multiple filters, it would be the following:
"1-star AND Open AND by assignee"
"1-star OR Open OR by assignee".
This is why the reviews disappear when using multiple-star ratings, as the system is filtering by "1-star AND 2-star" instead of "1-star OR 2-star," and it would be impossible for a review to have a rating of both 1-star and 2-star.
You can still use star rating, task status, and assignee filters together, as it is possible for a single review to meet all of these criteria, you just wouldn't be able to use multiple star ratings in the same set of filters.