Search > AND Search on 2 word combiniation (+<word> +<word> that is a minimum of 3 characters each and NOT known to exist in the site works as OR

AND Search on 2 word combiniation (+<word> +<word>), that is a minimum of 3 characters each and NOT known to exist in the site, works as OR.

Step to Reproduce

1. Log in as host

2. Create a page, and add html content "cat"

3. Create a page, and add html content "dog"

4. Run Site Crawler

5. Go to Search

6. search by +cat +dog

Expected Result
Empty result

Actual Result
Two items, one for the first created page and another one for the second created page. The "+<word> +<word>" should work as AND, not as OR logic.