@LawrenceGee Someone can jump in if I'm wrong but I think that means the port speeds on your modem & Deco are not the same.  Like the modem has a 2.5G port and the Deco has a 1G port.  

You said you have 100 Mps so you're getting everything you're paying for since it is below the 1G speed of the port.

If things are working OK, I don't think it is anything to.worry about.

  @BradLouKy 

Brad - thanks for the reply.  BTW, I do not have a modem.  We have fiber in my community, and the ISP connects directly to my Deco router, at the 100 Mbps speed.  It works fine.  I am getting a strong 5mghz signal to all devices. Also, I bought it new thru Costco, and they have a 90 day Return Policy, and I have no problems to date. 

So, I agree with you.  I will likely disregard the WAN message (I assume that is geared to folks with 1Gb speed); and just watch for any other major glitches in the next 90 days.

Thanks again for the input.  Much appreciated,

Lawrence