Lag and freeze during champ ban and selection has become a regular occurrence for me.

In this screen, I’ve selected Scorpion for ban.

Then in this screen, after being unable to lock in my bans, you can see that QS (top champ for opponent) is banned instead of Scorpion.
In each of my last three matchups, this was the case, with the game freezing up at this (and other) critical moments in the pre-fight screens.
Objectives done, logging out for the afternoon—because I don’t like it when this game wastes my time and pretends like it’s all fine and dandy.
Dr. Zola