The teachings are infallible, but the {Pope is only infallible on matters of faith and morals, and only when he announces that he is making a statement infallibly. Francis hasn't done that. We believe that the Holy Spirit prevents the Pope from pronouncing something infallibly if it's against Church teaching. And so far, that's proven to be correct.
So...letting divorcees partake communion is correct? He’s pronouncing it, and who may partake communion is surely a core teaching.
Like I said: “perfect except where it isn’t”.