Matchmaker Keeps Kicking Me During Champion Select/Ban

For the second time in as many days I have been kicked out of a match for supposedly not doing anything in champion select/banning phase.

In the first instance, I had selected a champion to ban, but the ban button didn't work.

In the second instance, I just got kicked for supposedly not selecting a champion. I had already selected mine during the pre-ban phase. Then, after the ban phase, I was waiting for the enemy team member to select his champion. When his countdown got to zero, the game disbanded, which I assumed was because he hadn't selected anyone. Then it turned out that the game was disbanded because I supposedly hadn't selected anyone!

Immediately prior to all of that, in another attempted match, someone else on my team almost ran out of time to ban a champion, and then he wrote in the chat box that the ban button wouldn't work.

I know this is not just a problem for me. How can I address this issue?