Orthodox Easter (we usually call it Pascha) is not always after RC and Protestant Easter, just usually. Occasionally it falls on the same day.
I, obviously, would say that our date for Pascha is the correct one – certainly it is the original one used by the undivided Church being based, as it is, on the Julian Church calendar and using the original tables for calculating the Paschal moon. The date used by RCs is calculated using revised tables and Gregorian dates. This was later also accepted by the Protestant churches but the RC paschalion was anathematised by several Orthodox synods and so all Orthodox, even New Calendar churches like mine, continue to use the original paschalion (with the sole exception of the Finnish church which some Orthodox consider heretical as a result).
I’d also note that our date for Pascha is witnessed every year by the miracle of the Holy Fire in Jerusalem, which only ever occurs on Orthodox Pascha. Whether or not you choose to accept the miracle is up to you, but I certainly do and hope to see it myself one year.
Hope this helps.