Forced to pick a banned champion

not sure how to get the bug it's happened to me twice where after banning it tells you that you have picked the banned champ and stops you from locking in but to others it says you are picking what you had chosen before banning. the last time it happened I had picked rakan and banned brand. up until it was my turn to lockin which then switched over to brand and whenever I hit lock in I gave me the error locking in champion message.