Linux Mint 18: Network manager not showing wifi access points

Laptop: Lenovo T410

OS: Linux mint 18

Kernel: 4.4.0-47-generic

Network card (output from lspci):

03:00.0 Network controller: Intel Corporation Centrino Advanced-N 6200 (rev 35)
Subsystem: Intel Corporation Centrino Advanced-N 6200 2x2 AGN
Kernel driver in use: iwlwifi
Kernel modules: iwlwifi, wl

Network manager: network-manage 1.2.2-0ubunt

If I do a fresh start with my Laptop, the wifi accesspoints do not get shown at network-manager applet. But the known network connections get connected and work.

After sudo service network-manager restart it works like a charm and the available access points are visible in network-manager applet.

Strangely enough, after fixing it with the restart of network-manager and then suspend and wake up it still works. Seems to be just the first boot up where it is a problem.

Used to work like a charm in Linux Mint 17!

How to debug?