Can't see bann button or can't click on it

When i am in champ select and i need to bann i can not place a bann 9 out of 10 times because or the timer at the previous player reached zero but in fact i just can't see his ban. Or i can click on a champ during my turn in banning but the bann button stays disabled. Leading tot penalties due to 'me being afk'. I have uninstalled and installed lol again and tested my download and upload speed and they were okay. Don't know what else to do.