Welcome! This comm serves as a place for documentation of tankies on the Threadiverse. My megathread here has a slightly longer intro
But, in a nutshell, lemmy.ml is one of 3 instances that are mostly run by Tankies (Those who simp for authoritarian governments that merely claim to be communistic (China/NK) or otherwise "fighting against the evil west" (Russia)) known as the "Tankie Triad". So they'll do things like spread the Russian narrative that Ukraine is "full of Nazis".
They'll also censor you (and later, ban) if you post things they deem to be against their "ideology" under one of 2 instance "catch-all" rules. Rule 1 - "No Bigotry" or Rule 2 - "Be respectful.
Yours got censored under catchall rule 1, no bigotry.
The unfortunate problem with .ml is that it also has the notoriety as being the "dev run instance " as well, so most instances are quite hesitant to defederate from them, unlike the other 2 instances (Hexbear and Lemmygrad) who are largely considered to be worse than .ml and widely defederated from. The main devs, dessalines and Nutomic are, unfortunately, hardcore Tankies. Nearly all censoring actions on .ml though are done by dessalines and another admin, davel.
So the next best thing we can do as users is a general call to "boycott" their instance and not post comments or posts on a .ml comm. To choose to post to and grow other alternative comms that are off-.ml, no matter how big the comm on .ml looks (this also just leads to a better overall healthier Threadiverse). And to document things as we go, like I've done here