The following question is very close to this question. When closing the lid of my notebook or going to hybernate and waking up my Ubuntu Mate 16.04 machine, the nm-applet shows, that I am offline.
Different from the linked question above, I am not offline, I am online, but it just shows that I am offline.
Restarting the network-manager service helped sometimes.
Anyways currently this does not seem to have an effect anymore. It is annoying because some applications like evolution appear to share the same source for determining the online status than the nm-applet. That means, that in this state I can not check my e-mails but browse the web.
How can I ensure that after waking up the machine from hibernate the wireless network connection is established well and identified as established?