I can confirm that rebuilding the Discourse site from scratch targeting v1.4.0.beta1 fixes the embedding. So it seems like some sort of regression has happened on the meantime (probably what @jqnatividad mentions).
I can confirm that rebuilding the Discourse site from scratch targeting v1.4.0.beta1 fixes the embedding. So it seems like some sort of regression has happened on the meantime (probably what @jqnatividad mentions).