Does lemmy sites or instances give you a reason why you are banned so you are not doing the same thing ?lsewhere? Or how do I appeal a ban

You must have said something that the instance found anti-communist, pro-capitalist/liberal, anti-china. you get banned if you get perceived as anti-minority, I think.

Notice how I said "the instance found". So it's not easy to convince them if you run afoul by accident.