When Damping Sphere increases the cost of a spell the UI shows the cost as the new “mana cost”, which gives the impression that the new cost is the cmc of the card. Which can lead one to believe it will not be countered by chalice of the void, as chalice refers to the “mana cost” of the spell. There should either be an update to the text of chalice to reference the original mana cost or on the modified cost to explicitly state that it is modified or different from the cmc.