The major difference I see is that there seem to be somewhat more Russian boots on the ground in Eastern Ukraine than there were American boots on the ground in Cuba, but any difference is marginal and hard to really measure. The overall approach seems to be the same. And there’s no reason to believe that regular Russian Army units are engaged at all (because if they were, the Ukrainian Army wouldn’t be winning!).
Don’t forget that, in order to make a proper Bay of Pigs comparison, it would require that the U.S. train, transport, and supply U.S. citizens to Cuba in order to make Cuba the 51st State.