Can't chat or ping without the cursor? [GAMEPLAY]

I was playing a game as Syndra. When I loaded in my cursor never changed from the white computer mouse arrow to the golden hand with a pointed finger. As soon as I got into game I couldn't type and my pings were completely bugged out. When I clicked and dragged to ping, the line that you pull to select either On My Way, Enemy Missing, Assist me, or Danger was super long and required me to like pull it all the way around very steadily. I couldn't just click and drag, nor could I do a quick ping to alert my team of danger. It would randomly choose a different thing when I'd try to quick ping.

 This really affected the game because I'd be pinging that I'm coming by accident, and so bot lane thinks they're getting a gank rather than getting ganked themselves. Communication was even further stunted by not even being able to type and chat (no, I was not on chat restriction). I tried leaving and reloading the game, which fixed the problem. It might not seem like a huge problem but it honestly felt like a big obstacle when you can't communicate.

 I'm really not sure how it would be possible to replicate this bug since it only happened to me that one time a few days ago. I take a while to initially connect to a game (I load in fine, though). I think I may have been trying to tab out before I initially connected, which is near impossible to do but sometimes I manage it. When I clicked back on the League tab on my menu bar the cursor just wasn't changing I guess. It usually doesn't change until we're right about to get into game.