Beatboxer, Combo: 4 damage to random enemy minions does not trigger twice after the new two-mana spell.
It would help if you said the actual name of the spell, so that we know what card you are talking about.
They’re talking about the card lucky comet, “Discover a combo minion. The next one you play triggers its combo twice.”
I’ve seen reports ages ago about the beatboxer being bugged with doubled comob where his second cast would only deal 1 damage