I can't reconnect to a game

I joined a rank game. My game opens up and says that I had a connection error and that I could retry or cancel. I hit cancel so I could reconnect from the client, which I think is safer. The problem is my client sends me to the home screen, instead of a reconnect to game button, which means I was unable to reconnect. I thought maybe they just took rank down right then or something and didn't think much on it, however, 5 minutes later, I ended up getting low priority queue where I have to wait time to play a game. It says I left a game, I am wondering how I should've rejoined that ranked game so that this doesn't happen again.

Edit: my computer is brand new and is pretty good so this probably isn't a hardware issue.