I recently purchased a Nighthawk XR500 router. When connected to my modem I'm only getting about 20mb download and like 1 upload. My wifi gets 240mb down and 20 up. I've replaced my ethernet cable and tried all four ports. I've also disabled QoS and enabled and doesn't seem to help. I've factory reset and rebooted and even left off for hours and still nothing. When connected to the modem my pc gets 300+down and 20+ up. V2.3.2.114 is my firmware version. I'm out of ideas so any help would be appreciated. My modem is a Nighthawk CM2000 and my provider is Spectrum just to help with hardware and ISP information.
