Unsealed Spellbook, D key is permanently greyed out?!

Hello! I've been playing a ton of Unsealed Spellbook Pyke as i find that the versatility it offers is too good to miss out on.

But as you can guess i've been running into the problem mentioned in the title: one of my summoner spell keys, my D key, (the one on the left, you F on the left and D on the right people are insane) has gotten greyed out at some point for the last two games, which has seriously impacted the gameplay as i was not able to smite, heal, ignite, etc, midway at 15-18 minutes or so, this has actually caused me to lose one of those games, this is a seriously damning bug that's made me avoid unsealed spellbook from now on until its fixed.