I have just had Comcast install the new xFi gig speed modem in my home office. I have two laptops hardwired to the modem, but I'm getting two very different speeds. The older laptop purchased in 2014 is an Asus with an external net gear ac network card. On this laptop, I'm getting 920Mps hard wired which is great. On the newer laptop purchased in late 2017 is a Lenovo with a solid state HD and hardwired through an insignia USB type c gigabit to ethernet adapter, and I'm getting 510 Mbs. The Comcast tech told me there is a setting on the laptop that is stopping me from getting the higher speeds. Can anyone help?