Game cursor not appearing in game

Okay, so whenever I go into a game there's a chance that the League cursor will disappear. I lock in my champion and get into the loading screen where the League cursor appears briefly before reverting to the Windows cursor. It does not change back when getting into the game which makes it impossible to click on anything, buy items in the store or even move my champion and apparently stops keyboard shortcuts (such as bringing up the In-Game options or Scoreboard) from working as well. I'm in the game and can't leave as I can't bring up and click the "Leave Game" button and have to wait and watch as my team pings me in the fountain before remaking (Which sucks particularly hard when it happens in ranked).

This initially started at the end of January, where I restarted my computer and the problem stopped. It's now back and having restarted my computer (which fixed it temporarily) it has started again the day after. I've tried tweaking the mouse settings as suggested by Riots Support page, tabbing out and back into the game, force quitting the game and closing and reopening the client (which just reconnects me to the game with the same problem) and initiating a full repair from the clients screen. None of this has worked except restarting my computer (which as I said before seems to only be a temporary solution).

It's getting to the point where I'm entering Practice Mode just to check if the bugs appearing before entering any games and even then it's not a sure fire way to make sure it's not going to start happening at random. It feels like a waste of my time (and LP) and my teams time and I'm genuinely considering giving up on League because this bug is more hassle than it's worth.

Note: I initially thought this big was exclusive to Sion as it was always him that it came up with, however I've just tested it with another champion (Gangplank ) in the Practice Tool and it is the exact same problem.

Any help would be greatly appreciated.

Thanks for reading this absolute word salad.

Edit: A friend has suggested turning off Discords Overlay. I have done and will update if the problem re-emerges.