At least Poland bans the display of both symbols
No it does not.
unlike Russia where the criminal sickle and hammer, red star and mugshots of serial killers Lenin and Stalin are prominently on display.
In Poland the hammer & sickle are on display in numerous locations, sometimes even accompanied by the socialist Polish eagle.
You might notice a difference between the ancient symbol and the modern one. Not only does it point in a different direction,
That's the key. Which way round did the one in Bialystok point?