Unable to select champ in champ select. [Client]

I was 3rd pick in a ranked game lobby, the banning phase went smoothly. But when it circled back around for me to pick my champion, I was unable to. I was hovered over Thresh, but despite all my efforts, I could not "lock in".

He was not banned, I owned him, he wasn't selected by anyone.

I am unable to recreate this issue and in a moment of panic, I forgot to screenshot the issue. Afterwards I queued up again, and after an unfortunate loss, I discovered I was demoted. This is an unfair loss of lp that could have kept me in the division I was currently in.