I may have the same issue but on bottles flatpak. For me, the game sometimes does this thing where the game doesn’t load, and when it does, it’s a 1x1 window (even though I am on gnome, not a WM) that I can’t interact with. I have had best reliability with having the virtual desktop enabled, and if the issue happens, open system monitor or whatever the equivalent of task manager on your distro is, and kill League Of Legends.exe, which closes the game and should let you press the reconnect button. I usually have to do this multiple times before the game decides actually make a window and load.