Wow bug (my friend isent able to play)

Me and my friends wanted to play wow toghter but one of them got some werid glitch He is getting wow loading screen all the time and his character isent at same position like it is at ur screen ( u can see that clearly in video)
once he get glitched he isent able to attack nor log out "He needs to alt f4" to turn off game. he tryed loading game in adminstrator,redowlanding, and his wifi is fine u can see that in a video
https://www.youtube.com/watch?v=mB911kbOtTo