Nope, Jihyo wasn't even particularly that popular and dating scandals don't really affect idols on the charts, it's usually the sales that suffer (like Daniel actually). Feel Special was their real departure from their signature sound and while it wasn't a megahit (as that was kind of a dead year for the charts) it was still incredibly successful.
It's further departure from Twice's sound, the refusal to develop solo careers and the encore stages that hurt them.