Client Champ Select AND accept match freeze

When hitting "Accept" during queue, the screen is stuck at the "match accepted -- waiting for other players" animation. It will eventually un-freeze and land me either back in the party, or in champ select already past the 'banning' phase.

Sometimes, it will be okay through the "match accepted" animation. It may then freeze during champion select, during any of the picking phases. The timer will countdown to "0" and stay there. At this point, the ACTUAL champion select phases are still going on, but MY client is frozen there. When it is my turn to pick, I am not aware nor able to click accept. Afterwards, I am informed that I have dodged the game and have been put on a timer. This has occured FOUR times in the last two days, and only recently started. Please, help me with this problem!!

My internet is plugged via ethernet, I get 1,000 mb/s. My ping in-game is between 10-20 ms and my FPS is well above 120 with max settings. Never any FPS drops, never ping spiked.

I lost my make-or-break game promotion to gold because of this bug, and a few LP obviously.