Yes. I have both the mini and a pro and the pro works just fine but toggling that in the main settings doesn’t help the mini.
And it seems like doing the request desktop site from the url bar in safari isn’t persistent. It works while you are on the site but once you close the browser or open a new tab it goes back to mobile.
Maybe it is a bug.
It was mentioned in one of the WWDC sessions that due to its size, the iPad mini would default to mobile vs desktop views.