Stuck in champ select

I am making the post on behalf of my brother.

While he can see most of the steps to be able to play a game, he always gets stuck in the champ select screen.

He can click in his preferred champ. He cannot pick any champ in select after the ban phase. We tried everything from uninstalling, fresh install to repair and countless other things. it seems he cannot play League on a brand new "uber" gaming PC. It's becoming very frustrating.

He basicaly gets timed out and gets an increasing penalty every single time. Most of the evenings we try a couple of times to get a game started, but nothing seems to work. We have tried it in ranked and in draft pick, but he can never click in his own champion. he can "prefer" it and he can ban other champs, but he sees nothing when he needs to click in , except a greyd out button and a timer of the previous phase that gets to 0.

Any hints?