My Wired connection to an Orbi Satellite is slower then my Wireless to the same Satellite

[Camdiggy]

I have xfinity 1 Gb service to the house and a xfinity xfi modem in bridge mode.  The xfi model is connected through a CAT7 eithernet cable to an Orbi RBK843 Router.  The Orbi Router is about 45 ft from my home office and an Orbi Satalite unit is next to my desk in my office.  My desk computer is wired into the Satelite also with a CAT7 ethernet patch cord (I also tested it with a CAT5e).  According to the Orbi app, both my iPhone X and my desktop are connected to the same Satelite.

When I run a Speed Test on my iPhone X connected wirelessly I get 600-700Mbps

When I run a Speed Test on my PC I get 200-300Mbps

I have swaped ethernet cables with no change.

The network adapter on my PC is a Killer E2500 Gigabit Ethernet Controller.

The PC is running Windows10.

Why do I get slower wired connection then wireless connection to the Orbi Satellite?

[FURRYe38]

Be sure the drivers for the adapter are up to date.

Disable any QoS settings on th ethernet adapter. I believe some Killer adapters have this featuers. 

Please try the PC while connected to the RBR.

Try a differnent PC or ethernet adapter connected to the RBS.