AFAIK they've started doing it long ago. Not always this obviously, but pretty much right after 1945. And after 1985, there was no more pushback against it. The new, capitalist government of Russia was only happy to join in on the chorus of "both sides" and only started trying to play damage control around 2010's. Even then, they can't actually examine USSR correctly - as it would reveal their own shortcomings.
And when it comes to the Nazis, well. What actually are we taught in schools about them? We're told "they evil", but are we actually told why they are evil? For Russia, they are an invader. Okay, cool. That should be enough, right? But there are many invaders. Napoleon had also invaded, should we feel the same animosity towards France?
What else? Oh right, the Jews. Show of hands, who actually likes the Jews? Anti-Semitism is on the rise globally, Jew is used as a slur. Is it any surprise Nazis are getting praised? They were killing Jews, ergo they must be good, thinks the fool raised on capitalist slop. Why, perhaps it was the Jews themselves that organised the whole shitshow to sow discord between Great European White Nations, between Great German People and Great Russian People! That's the shit we are already seeing crop up.
And all of it boils down to lack of class consciousness and diamat.
Look at the pathetic Nordstream "investigation". They're already there