We have collected a lot of evidence from many customers now for whom the Airbus did not follow the route as entered in the MCDU.   In the vast majority of cases this was caused by missing information. The users mainly forgot to enter the weights, etc. in the INIT B page. Note this is NOT a Boeing, the INIT page has two pages in an Airbus, INIT A, where you fill the route and flight related stuff, and INIT B where you put in the weights and fuel related information.   If