By any chance, was anybody of you playing while using the team voice chat?

I just had the same problem right now first time in ranked.
Didn´t even update anything on my system. Yesterday I played like 6 matches and all were fine.

Gotta be something else. In my runner this file exists and I just got the speed bug.

Which Wine-lol version are you using? Here I am on lutris-ge-lol-8.7.1

Maybe a suggestion that may help: I realized that is not the only way to restart the game. You can close the client when you see the RECONNECT button. Shutdown the riot launcher gracefully. Then start it again.

After switching to lutris-ge-lol-p8-12 I had to reconnect and the game was not broken. The speed was totally normal. Unsure yet if this is generally the case or I was just lucky, as I am slow to replicate such states.

I must say I have witnessed, after switching to this runner, the escape of the mouse cursor in gnome. Once I managed to get it inside again, however, it never lost it again. Will keep an eye on it.

Are you using GNOME?