Intel Dual Band Wireless AC 3160 slow Connection and only 2,4 GHz

Hello there,

I have a Zotac ZBOX CI540 nano plus ( Intel Dual Band Wireless AC 3160 ) with Windows 10 Pro and Intel PROSet / Wireless 18.21.0 drivers .

Unfortunately I just get a 2.4GHz connection with 72Mbits .
Previously, I had Windows 8.1 on the computer and the same problem , with the new drivers . With the an old driver ( version 16 ) I had no problems and over 200 Mbits .

My router is a Fritzbox 7490th

Since the location of the router or the computer has not changed . So it's definitely a driver problem .