Kicked from champ select, even with champion selected

I enter champ select for 5v5 draft mode. I pick my champion at the preparation phase, where everyone chooses the champion they "might" want to play.

I lead with Tryndamere, as my team leads things such as Noct and Annie and Kai'sa.

My turn comes, and with Noct, I wait out the timer. I was hoping to think of a counter-pick since the enemy team choose Rengar, Yi, and that girl with paddle star. But I did not.

My round of champion select ends, I am kicked.

Since I had a champion picked at the beginning, Tryndamere, and he was not banned, I do not know why I was kicked!

I read previously, that being kicked for not locking in is a bug. I am asking you to figure out if it is a bug, or the intended behavior. Note that if it is- this is very weird! Just choosing a champion was normally enough to not get kicked, and I expect that is the normal behavior.

I suppose you might kick people for not locking in, but I do not know that, so I am filing a bug report.

-As far as I can tell, this is the 100% consistent behavior. Why? I do not know. -This has been consistent throughout season 8, and maybe before I don't remember -What is the intended behavior here? -If I it is not, please change the message to "failed to lock in a champion" A clear message is a good message.