Some time ago I noticed that the internet on my laptop HP Z Book 17 G3 is very slow . On a daily basis I use the wifi network in my office . I ran the speed test that showed max . 0,4Mbps !! What's interesting when I connect the laptop to the same router via ethernet cable internet begins to operate at normal speed of about 17Mbps From the moment a problem occurs, I installed the latest drivers ( 188.8.131.52 ) for the wifi card (Dual Band Wireless - AC 8260) and the latest Bios Version (N81 Ver. 01.09)
I did a lot of tests by installing the latest and old drivers. Changing the router, and so on.
Finally, I mentioned wifi module which today came from HP service.
Problem solved. The first tests showed that everything is working properly.
The full test will do in the evening but it seems that everything is ok