I have disabled both of them and got my results properly sorted by "Price: Low to High" while with both extensions on, it defaults to Featured!
Here's a tiny portion of a massive error message:
Error logged with the Track&Report JS errors API(http://tiny/1covqr6l8/wamazindeClieUserJava): {"m":"undefined Unknown error","name":"Error","csm":"v5 ueLogError stack","logLevel":"ERROR","attribution":"APE-safeframe","pageURL":"https://www.amazon.com/s?k=mastering+perl&s=price-asc-rank&ds=v1%3ANxZp5S66jp%2F1FIQyOG0JNqN4D96zzLqBks5YP1xArBo","f":"https://www.amazon.com/s?k=mastering+perl","l":2039,"s":["logError<@https://www.amazon.com/s?k=mastering+perl:2039:60","importScript</script.onerror@https://www.amazon.com/s?k=mastering+perl:2039:267","EventHandlerNonNull*importScript<@https://www.amazon.com/s?k=mastering+perl:2039:230","@https://m.media-amazon.com/images/I/61ZS63EQSsL.js?AUIClients/AmazonUIjQuery line 44 > eval:1:372"Comparing to FF with both those extensions, the items and their order look identical (minus some ads)
You might have customized uBO beyond default settings/lists, and this is causing your issue. If you think this is a filter issue in uBO, please submit a report using the _chat_ icon in the popup panel[1], this will provide us with all the information we need to start investigating the issue.
[1] https://github.com/gorhill/uBlock/wiki/Quick-guide:-popup-us...
So if you sort by price you get the strangest crap at the cheapest end.