I may have got this wrong, but what I am just about to say just worked in WP8, and just doesn’t work in W10/W10M.
I used to be able to track flights in Cortana, which gave me notifications at the airport on delays/gate numbers etc… Those notifications don’t work for me anymore – and to add, I thought Cortana was now able to take that information out of your outlook.com email account – never worked for me.
Secondly, when going to an appointment/event – with all the details listed within the event, it doesn’t tell me when to leave, or the directions…
Cortana seems to be going backwards for me rather than forwards. (NOTE – I’m in the UK, so could this be a regional problem?)