Bag in hotkeys (shift key disables movement)

i had this problem for a long time and today just figured out what is going on... under the player movement options on a "player attack move click" if i set anything except default shift + MB2 key then pressing shift key disables player movement

can anyone confirm this bug? i googled and many people have same problem shift key disables their movement and i figured that it is caused by player attack move click option