I also tried with Firefox.
Besides the test site, we have 2 sites, on different servers, with very different templates... one is on VM 3.8.4, the other is VM 3.8.8.
I cannot create a 404 error for wrong product URL, in any of the sites, no matter how hard I tried.
I always get shown the category with 200 status code.
example:
myfakesite.net/category/subcategory/myproduct1 <--- valid product link, works ok
myfakesite.net/category/subcategory/myproduct1-randomwordsshouldntwork <---- invalid product link, status code 200, shows subcategory page
myfakesite.net/category/subcategory/doesnotexist <---- invalid product link, status code 200, shows subcategory page
Things I tried:
VM 404 handling turned off (also tried enabled)
Joomla caches turned off.
Different browsers.
Different templates.
What should I try next?