[GAMEPLAY] Can't change rune page in champion select

Since the most recent patch, or whenever Rune Page names were changed to the bold font, I've had this happen twice:

I'm in Champion Select, and I'm choosing the rune page I want to use from the drop down menu while the timer is counting down until the game begins. I'll select the page I want from the menu, but when the menu closes, it says the name of the previous rune page, and I can't get it to switch. In-game, I am stuck with the runes on the named page, not the one I selected, and my team and I are at a disadvantage.

EXAMPLE: The client shows my current rune page as "Rune Page 1." I try to switch it for a rune page named "Poke Support." I open the drop down menu, click "Poke Support," the menu closes, and it still says "Rune Page 1." I try again, the same thing happens. In the loading screen, I see the Keystone and Secondary I have on Rune Page 1. In game, I have Rune Page 1 runes.

I've tried to reproduce the bug in custom games several times, and succeeded once.