In some global url rules built-in ad blocker doesn't block ads if the rule appears in uri query, but not in path.
For example, some rules from EasyList
/adlink? /adlink_ /adlinks. /adlinks2. /adlinks_ /adlist_ /adload.
<img src="http://example.com/index.php/adlink_"> <img src="http://example.com/index.php?id=/adlink_">
The first image will be blocked, but not the second one.
Any of the other ad blockers (ABP/uBlock Origin) will block both of them, using the same filter (pure EasyList in this case)