Hi there,
I’ve had this problem for some months, it ruined a lot of champselects.
Here I first selected Xin Zhao, changed my mind and went for Xerath, but I get Xin Zhao.

I’m actively playing league on linux for years and this wasn’t a problem before. My friends on windows don’t have this problem.

lutris-ge-lol-p8-12-x86_64 (default)
lol patch 13.18 (current, but also before)
used lutris for installation