What's wrong with propaganda? Is that a reason why you haven't seen for example Apocalypse Now?

You might want to watch Andrei Rublev, at its inception a controversial movie heavily disliked by the Soviet state:

https://sovietmoviesonline.com/drama/andrey-rublev

Edit: And then the post-soviet Fairy, which ruminates on the legacy of Tarkovsky's masterpiece.

https://sovietmoviesonline.com/fantastic/fairy

The rest of Melikyan's movies are also quite interesting and fun.

They also distribute post-Soviet russian movies and television series. You should watch the two takes on The Master and Margarita, both high profile projects based off one of the most beloved books in Russia, from two very different times in russian society:

https://sovietmoviesonline.com/drama/master-i-margarita-mini...

https://sovietmoviesonline.com/melodrama/the-master-and-marg...

The Soviet was especially good a adventures for kids and science-fiction, of which you'll find a lot there, for example Alice in Wonderland and Hard to be a God. You should watch the takes on the latter to get a feel for differences between soviet and post-soviet societies. If the younger version feels hard to watch you might need to watch The Green Elephant and other movies from the russian nineties to prepare yourself and better understand the feelings and mindset of the time.

And if you want you can watch old propaganda movies about the Donbass or whatever, you'll learn a lot about places you likely know very little about.

Movies done behind iron curtain, despite (and sometimes thanks to) everpresent censorship and oversight ended up with pretty deep existential messages that avoided usually not that brilliant censors.

Bear in mind that most artists abhored oppression even in toughest times, they are all free spirits after all, and I can imagine also in current russia there must be at least large pockets of similar folks.

Of course there were more shallow mainstream things more or less full of propaganda, and many actors overlapped between 2 categories. If one was clearly in critical camp then no work in industry, either some menial soul breaking job, prison or kicking out