Hi! I could reproduce what you described and I also have the same problem but with runes, so if I switch rune pages then try to edit the one I selected immediately, the previous rune page shows up and gets selected again. I have some similar issues disenchanting shards in the hextech crafting screen as well.

From my (superficial) understanding, I believe this is a Wine web socket problem. Wine seems to introduce some additional delay when communicating with the servers via the League client, so what ends up happening is that the the client's UI updates faster than the server can receive what we're doing and process it.

My source is a comment in this reddit post. 3rd/4th comment, the one by Tsubajashi, and the response from ZoeyKaisar. This post is cited in the LeagueOfLinux website in Optimize -> System and Lutris Optimizations. Since this is a year old comment and we're experiencing this issue to this day, AND given that the problem isn't mentioned on the website, my guess is that by now this is unfortunately considered normal.

My workaround has been to give it an extra second or two between every important click in the client and another action. So no more last-second picks, bans or changes for us while someone comes up with a real fix, but this should be a small sacrifice considering we're able to run the game itself almost flawlessly!