Only a fool will think that Russia who took Armenia, Azerbaijan actually entire transcaucasia from Iran just 2 centuries ago will allow Iran to regain its power in the region. Its not in their interest and I understand it from their POV, they have their concerns of the growing Iranian threat/influence in their south, Iran and Russia fought for centuries in the Transcaucasia, governments might change but history does not.
They are not the be blamed a bit because them as a cornered Eurasian state are looking for their own interests. Question remains is Iranian state looking for its own or not ? These YAK-130+SU-35S+Murmansk EW deal happened because of Ukraine war or the build up before, why did Iran not corner Russia into TOTs or any fighter airframes they could have gotten when Russia needed Iranian military and political support ? Iran was more interested in supporting Sunni arabs that, given the opportunity would prefer to fight Iran than Israel who bombs them daily. Our leadership is dumb. Whatever weakness Iran has in relations with Russia is not because of some Russo supremacy but its becasue Iranian leadership is illiterate and refuses to learn from past. Russia backed out of Mig-29/31 deal in 90s, it refused Kilo submarines retrofit, it supported sanctions on Iran in 2009, refused S-300, refused RD-33 turbofans and SU-35S will follow the same fate but IRI refuses to learn. Only solace is that apart from IRIAF, other branches went for their own tech. Bavar-373+Mehran pisses on S-300PMU2, Iranian shipyards retrofitted Kilos at home and went ahead with their own Fateh, Besat, Ghadir. IRIAF remains the slow brother among the bunch.