Jayce Cannon form bug

I played a couple games of Jayce recently and found a probable bug with the first attack debuff when switching to his ranged cannon form. When attacking a tower I would use hyper charge for more damage on it but I found that afterwards, if I tried auto attacking an enemy unit, champion or minion, the debuff would not apply and on Jayce's status bar, the icon for it to happen is still there (I hope that makes sense). I found that either switching between both forms would solve this problem or by waiting for your hyper charge active to come up and attacking an enemy unit would fix it.