Odd problem with microphone mute/F7 key after update

This is a bit difficult to pinpoint, but it's the second time it's happened to me after a league update. I use a Blue Snowball microphone, which doesn't have a mute button attached to it, so I use a third party program (micmute) in order to mute it. I have it bound to my F7 key, since I don't use the key for anything.

About 8 months or so ago, I updated League and I could no longer mute my microphone if I was tabbed into the game. Even just the client without being in game, I cannot mute using the program/hotkey. If I click outside of the client, it works completely fine once again. This lasted about a month or so until another patch was released, and it was back to normal.

It seems that with whatever patch I just downloaded when I logged on an hour ago, the problem is back. If I'm tabbed into the League client or in game, I cannot mute myself using my hotkey. If I tab to anything else, it's completely fine. No other game has ever had this problem. It is League specific. I have no hotkeys in League bound to F7. I have no idea what the cause might be, and I'm more confused since it was fixed and then randomly appeared again. Any help at all would be appreciated.