If you're referring to Google's URL Inspection function, I've found when I run the inspection, it gives you a "not mobile friendly" answer. Then if you View the page inspected you see the desktop version plus the mobile version on top of it. However, if I run the test a day later, it works properly. In fact, the first display that you see (mobile version on top of desktop version) was exactly what I saw when I used my Google Chrome browser to display a just-published web page before someone suggested that you need to first clear the cache on Google Chrome.