I have this experienced last week at least 5 times.
I have a very good new pc and good internet (usually play with 18 ms, 100 fps) I never have ingame problems.
However the cljent is tripping balls in champ select. This happens; someone has to pick their champion, it counts down to 0, then boom freeze. I keep seeing the screen but nothing happens. Weird enough the chat still works. After 2 minutes I am kicked out of the lobby and have to wait 5 mins because I 'left the lobby'
On my alt account I lost LP in ranked lobby due this horsecrap.
Please fix it