Hello from Russia!
I think it depends on to which part of Russia you are writing. For example, there are my stats for the Netherlands:
I’m from Nizhny Novgorod (it’s in the European part, in 4 hours from Moscow by hide speed train). It usually takes a card about 15-30 days to reach me and 20-30 or a little bit more to get to the Netherlands.
And also the time when you send the card (= when it’s about to arrive to Russia) may also be the reason. Because post offices don’t work during the holidays (New Year and Christmas, Women’s day, Day of Defender of the Fatherland, the 1st May, Victory Day, etc) the card may be given to the receipt several days later after its arrival.
And being honest, not all our post offices work well. And as I recently read on the Russian part of the forum, there may be cases when your postman is sick and there’s no one who can deliver your cards, or it also may happen that a postman suddenly quited their job…
So, I don’t think that the reason is in you. Everything is different, things happen. It’s always really sad that a card travels for a long time or is expired :c
I suppose that the only things you can do is writing addresses the most readable they or printing them, try to place stamps a little further from the meaningful parts of the address (name of the street, number of the house and flat, index). If it’s possible write the address in Russian, some people believe that it may help (but I don’t recommend to do it if you are unsure if you did it right, if you found the right Russian equivalent for the street’s name, etc because we use abbreviations that only we can understand like ul., pl., prd. and others as in the same city may be, for example, ulitsa (street) Sovetskaya and square (ploshad’) Sovetskaya, etc).
It really doesn’t matter. Someone starts with the city’s names, another starts with the street’s name… But write as the receipt requested!
The only thing I really can wish you is to stay patient and don’t become disappointed, cards will arrive one day It always takes time, especially now.