I’m not anti-communist. I’m anti-authoritarian.

Part of being a communist is recognizing what it means to even be "authoritarian." It means (among many other things) that you have examined that word and it's various meanings and how it holds up to what's really happening in the material world, and how it relates to the way societies actually work. Not just some nebulous "vibes" regarding what kind of images float around in our heads when the word is spoken. In other words, materialism vs idealism.

Being a communist does not imply supporting Russia, because Russia is not communist in any way, it’s a dictatorship.

I doubt you could find a single communist who believes that modern Russia is communist because it isn't. We all can agree that it is not. Likewise I think every communist you could find would say that modern Russia is at best a disgusting capitalist disgrace to its Soviet history. But to call it a "dictatorship" especially without also recognizing other capitalist nations similarly as "dictatorships" is just a failure of understanding of what that word means, but I won't say more on it because ordnance_qf already did. So let's move on to "support" of Russia. As a communist (Marxist Leninist, aka "tankie") I do NOT support Russia in its capitalist endeavors. Again, I doubt you can find a communist who does. But I can still look at Russia's position on the world stage at this time and see that because of its material interests (and not because it's "the good guy" - it isn't, and not because it's current government has noble intentions - they don't), it is supporting the global south in the latter's struggle against imperialism. And it is US imperialism that is the boot on the neck of the peoples of the Global South. For liberatory revolutions to be able to survive before being strangled in their nascency, the pressure of that boot must be reduced or better yet removed. What I support is Russia's undeniable help in facilitating that. Which is what we as communists mean by "critical support." We highly criticize Russia, but we support it in it's primary fight against the US, NATO, and Western Imperialism (which are all aspects of essentially the same thing) for the sake of revolutionary movements that would thrive were it not for western suppression.

Being a communist also does not mean being pro China, because even if China implements parts of communism, communism does not imply eradicating the identity of minorities and censoring whatever the party does not like - i think communism, free speech and a multicultural society do not exclude each other.

I would agree with you that support of China is not a prerequisite of being a communist and there are many communists who do not (including many communists who the anticommunists on this instance would still call "tankies"). China doesn't "implement parts of communism" but China is a Socialist project (where the word "socialism" refers to the transitional stage away from capitalism and towards communism, since unfortunately communism cannot spring fully formed into place). You can be highly critical of China's socialism as many are, but at the very least capital does not enjoy a dictatorship in China as it does in so-called "liberal democracies." However, when you go on to say things like China is eradicating the identity of minorities or the implication that it is not a profoundly multicultural society, that is where I just have to firmly disagree and call "BS." Of course communism and a multicultural society do not exclude each other - they can't exclude each other, by definition. China is very far away from perfect, but to say it is against multiculturalism or worse that it is "eradicating the identity of minorities" is simply the repetition of lies that you were told, lies originating from a state that considers China its arch nemesis and despises it. It's propaganda. This can be confirmed even by going there. So by all means, criticize China, call it out for its actual faults, but find out first what they really are and do not perpetuate demonization, literal sinophobic falsehoods.

I went into a lot of detail in this response because I think that you and I (and therefore many "tankies") are not actually on very dissimilar tracks, and likewise I suspect with a lot of other people reading this thread. But there is just so much bad faith I see in threads like this, it makes it all but impossible to see the similar tracks. And I think that is often by design. Like another comment I responded to (and tons more I didn't) that just want to smear and demonize without even a hint of a desire to understand, but your comment clearly wasn't like that, and you expressed honest, valid (though towards the end, I would say gravely misled) concerns. I'd bet there are a lot of people who listen to the "tankies are evil red fash" noise and just assume that must be the case without any actual engagement and never actually take the chance to understand the actual position. Those of us who genuinely want sincere, unselfish human flourishing, should be able to find that common ground to actually suss out our positions and learn. But the smarmy and smug anti-tankie crowd do not want to learn and they do not want others to learn. Fortunately many still will, despite them.