BlackBerry is now rolling out OS version 10.3.1.1779. I am not sure at this time whether this update is available to all BB10 smartphones, but on my Passport, it is an 80MB download.
It is also not clear yet what it fixes or adds. Hopefully, it fixes the screen flickering issue on the Passport since the last update.
Have you gotten a prompt for this update? On what device? Do give us feedback.