I heard about this movie from a friend, so I don't have exact details.
The story is that a man from a Soviet Russian town goes to work by train in the morning, and returns in the evening. He falls asleep on the train ride home and wakes up apparently in his town, walks to apparently his block, his building, his floor, his apartment, unlocks his door with his key, but the family inside is not his. The twist is: he woke up in the next town over and all the towns are so much cookie-cutter exactly the same that even his key opened the door.
As far as I can tell from the context it is a 70s or early 80s movie. In my opinion it falls under fantasy (not so much SF) and it definitely seems like a commentary on the uniformity of Soviet era towns, planned economy, and banality of modern life under such circumstances. It is a wonder how that seemingly negative context was allowed in those times (unless I'm mistaken about the timeframe and this movie is from the 90s).
Can you help identifying the movie and even better a streaming link to the movie?