[GAMEPLAY] Hotkeys randomly cease functioning

For two entire games now, my hotkeys have simply stopped working. All of them. I have attempted to rectify this by resetting my hotkey settings, but to no avail. This has occurred with two separate champions (Warwick and Veigar) on two separate occasions--my only recourse (aside from attempting to fight by manually clicking on my abilities and then clicking the target, which is time-consuming, impractical, and often fatal) was to apologize to the team, head back to base to avoid feeding, and faff about until the game ended one way or the other. How may I fix this reliably?