Black Screen During Champ Select But Still Can Hear Audio

THIS BUG COST ME 2 INVISIBLE LOSSES ON MY PROMOS - So basically I queue for a game and then I find one and hit accept. Once it transitions to the champ select screen I can hear everything in the champ select but nothing on my screen is changing and it's just blank. It kicked me out of queue and now I have a 28 minute dodge timer and reduced MMR since I "dodged" in promos. If this bug continues after I restarted my computer and client it would have cost me 3 promo games and ruined my placements. Riot please look into this.