This is not a blackberry company site but someone may be able to answer your question. I would suggest you go to the Blackberry company forum site for a look. Device Support Forums - BlackBerry Support Community Forums
Also a search on the internet shows a lot of customer complaints with the OS9 upgrade. You might also look there.
this is just one site with some of the issues . Looks like Apple did a rush job on the OS upgrade. One listing indicates Cell LTE issues. None specific to Blackberry so it may be widespread. 10 Common iOS 9 Problems & How to Fix Them