Xbox One S negotiates only 100Mbps down/up speeds when connected directly to G3100.

Xbox One S negotiates only 100Mbps down/up speeds when connected directly to G3100.
I have recently upgraded to the 1Gbps Fios service and received a brand-new G3100 router. When my Xbox One S was connected to the G3100 router through a Netgear GS308 switch, it clocked at ~800Mbps download & ~25Mbps upload speeds. The download speed was
awesome and the lower upload speed was not a big deal and consistent with other posts I found online.

However, after I connected the Xbox directly to the G3100 router through the same cable and hoping to increase the upload speed, I started getting only ~96Mbps down and ~90Mbps up. The G3100 Web GUI shows that the G3100 LAN port to which the Xbox is connected
is auto-negotiated at 100Mbps Full-Duplex. I tried to force the port to 1000Mbps but after about 30 seconds the router reverted back to 100Mbps.

I did a full Xbox restart and a full G3100 restart several times, swapped around cables/connections but whichever LAN port the Xbox is connected to continues to negotiate as 100Mbps Full-Duplex. By now, I am pretty confident that the lower speed is related
to the Xbox-G3100 negotiation. I have three other devices connected to the G3100 and all three negotiate 1000Mpbs Full-Duplex without any trouble.

The G3100 is supposed to be state-of-the-art but I am frustrated that it seems to fail at such a simple task as negotiating a hard-wired connection. Are there any settings I should change on the router or the Xbox?

:)