I have written comments about this before, but the very simplified guide on, how to spot the russian and chinese propagandists on lemmy, is:

• Defending russian invasion in Ukraine, defending genocide of the chinese minorities, claiming Tianamen square massacre and the treatment of uighyr people are a hoax, being racist towards tibetans, doing the "I do not support [them], but..."
• Equating the USA = NATO, claiming everything any NATO country does is NATO as a whole doing it, blaming NATO for trying to attack Russia, saying NATO is trying to expand when border countries are joining voluntarily, blaming small border countries for aggression towards Russia
• Talking about "the West", starting to speak about colonization times in unrelated discussions, trying to dismiss you by blaming you or you country for European colonization
• Trying to downplay and derail discussion on what Russia/China does, because the USA/"the West"/someone else has done bad things as well
• Writing longer and longer responses with multiple claims, often so you have to look into their sources/find reliable sources on the things by yourself, so you can argue against, in attempt to tire out out by making you answer each claim individually
• Using chinese state sponsored sources, supporting pro-russian/chinese politicians
• Blaming you for supporting genocide in Gaza, when you talk about some other genocide being bad, especially if it is related to Ukraine or China
• Dissing capitalism and saying China and/or Russia are true communists, marxists, etc., supporting the governments of China/Russia, either directly or hinting they are Better Options, arguing against calling China/Russia authoritarian regimes

You know, you found them, when your comments saying anything negative about Russia/China get downvoted, or someone starts arguing against you. Essentially there is no difference between the useful idiots and the bots and propagandists themselves. The people honestly identifying as tankies or defending tankies, are hanging in the metaphorical nazi bar without realizing it, and will not change their opinions, because they belive you are either bad, or brainwashed, so arguing does not get you anywhere.

The easiest way to deal with these, is to block the and move on. Arguing against will only give them more visibility, and make you tired and angry. If you feel pissed off, just explain these points as an answer, so others can consider with a different perspective, what they are reading, then block and move on.