I have gigabit internet service through spectrum. a Nighthawk AX8 Wifi 6 router. my nighthawk app on my phone shows that the router speed tests at around 900 MBPS. i have a custom PC with a Asus Z170 motherboard. the computer is hard connected with a cat7 ethernet cable that runs about 50 feet to the pc. no matter what i do i cant get my PC to speed test higher than 300MB what do i do?