Loading Screen Game Crashes, Subsequent Inability to Reconnect to the Game

So, this account is level 12 so I probably don't matter as much as the level 30's, but let me first say I'm enjoying myself playing this game, I was, that is. About the second time I have had this issue happen is when I start to ponder whether or not this game is truly functional on a full-time basis or if the most recent patch has done, as people seem to suggest, and broken the functionality of the game.

The issue, as it is, stands as a client issue to me. What will happen is I will be in champion select one moment, and then when the loading screen comes, the whole thing blacks out, and I am notified that I am unable to connect to the game based on my network settings and other allowances that may be hindering the internet and its connection with Riot's servers. Now, I know that's false because before I ever played the game I checked my firewall and other settings because they have hindered my performance in other online games and the last thing I want to do is go into a game and be the person not connected because of YOUR client and YOUR mistakes. I've made sure that my accessibility is opened up to Riot Games, League, and the associated folders, so why then do I have to suffer and make myself look like the kind of player that will go into a game and then immediately not play?

I know it's something even stranger when it doesn't persist past one game, considering I tested myself in a custom game immediately after the missed game finished, which was a surrender by my team, no big shock because I wasn't there to help them because of this infuriating issue. I was able to connect to and function in a custom game entirely normally, so why then, did the first game I try to play today have to make me look like the bad guy as a result of some errant error on Riot's end? So far as I am entirely aware my ISP runs just fine with it. I know it's a recent thing too, because the friends I have been learning from and watching have never had it until patch 5.12, and 5.13 respectively. I'm curious to know what was in those patches that has caused this hiccup in functionality, or if it will even be recognized by Riot as a mistake on their end instead of having this end up like every other thread regarding this issue where the player is redirected to the connectivity issues resolution area where they are then told through impersonal instructions that it is essentially their fault because the internet doesn't like them.