I noticed that Google Shopping and Walmart are doing the same, I can search for (e.g.)4.0 and get results for 3.0, and it's not by accident.
I can imagine the people implementing these (predatory) changes are not stupid, mistaken or fooled, but are doing this on purpose knowing full well they're pissing in the well that they will then be forced to drink from.
I only ask, why?
>causing me to purchase the wrong thing
That really is your own fault and has nothing to do with Amazon or Google, read the description before buying.