WIFI connection speed

Hi all, I would be happy if anybody can help me:)

NTB Latitude E6410 and compatibility with Modem Compal CH7465LG...

With the previous modem I had no connection issue, but now I have the new one (because of higher announced speed). But the connection and speed are really good only with cable connection (aprox 200Mbs). But via WIFI connection the speed is very limited. Connection is available, stabile, but speed is only about 100Kbs!!!

All other devices are connected with full speed (Android mobile devices, NTB Dell Latitude E5440,...), only E6410 with limited speed.

Connection seems to be OK, even with another WIFI connection (Mobile WIFI hotspot)  there is no limited speed.

I have tried to update drivers, but still no change, WIFI channels change also without effect...

I am really getting crazy with that, can anybody help me?

Thanks, Ondrej