Router throttling download speeds

I've spent the entire day yesterday trying to figure out why my router is giving me issues. Maybe someone here can help.

I have a Nighthawk AC1750 R1600v3.

When I plug in my PC directly to my modem (provided by Spectrum) I get around 900-1100mbps download.

When I plug it into the router, it hits from 200 to 700 mbps at the most. I'm not sure what can be causing it. I'm using fresh CAT 7 cables, I've updated the newest firmware and Factory reset twice. Something about the router is causing speeds to drop. Any help would be appreciated.

I'm resigned to assume that the router is malfunctioning(I've had it less than 2 years).

Any suggestions would be appreciated.