A lot of Eastern European countries have oligarchs who largely made their fortunes with help from the Russians. In Czechia one such example is the prime minister Andrej Babiš, who was a bureaucrat in a state owned business who then sold it to himself in the 90s (with the help of some "Swiss" money) and became a billionaire. He's consistently been as pro-Russia as he thinks he can get away with (the positive is that Czechs hate Russians a lot).

Also in these countries there's a lot of old people who have never been able to adapt to living in a free, capitalist society, so for them, there's some nostalgia for communism.