Bard ult bug [GAMEPLAY]

Was playing bard when the icon of my ult was off cooldown but i couldn't use it. I knew i couldn't use it because i used it not too long ago.

I had this bug after i i died before my ult's channel could finish, the bug was fixed after i casted my ult again but it was really annoying that i couldn't see when was my ult up or not and it really confused me.

HELP