Can't ban

Some reason I can't always ban on my turn in champion select. I select a ban, but I can't lock it in no matter how many times I press the button. It keeps just refreshing and then kicking me out of queue, and taking away about 20 lp every time. Sometimes it won't even recognize that I selected a champ, and lock in isn't even an option. I've lost at least 100 lp and it's irritating because I'm trying to rank up, but I can't do that when I get random automatic losses for dodging when I'm not