I have seen in the past little while that there have been a number of problems with Laravel's Sessions not being saved across views. A lot of the times this is because of a change that was made between Laravel 5.2.26 and 5.2.27
Double web middle-what? Laravel recently changed the way the default middleware works. The web middleware is in charge of items like Session Data, CSRF protection, etc.
In Laravel 5.2.26 they moved the middleware into the routes so that you could easily put routes outside the middleware (such as api routes). However there must have been some issues as they moved it back into a Service provider in 5.2.27
Lucky the fix is an easy one and there is a video for it and it is (free):