The channel bar resets itself (to full), but it still seems to end after the designated time of the original cast anyway (about halfway through the new, slower decreasing channel bar, the skill stops, sometimes but not others.

Not sure if this effects heroes with similar spells. But I noticed it when practicing with him.

I think this is bug? Surely any effects shouldn't take place until the next time the spell is cast. Sorry if this was posted in the wrong place!