@VousDeux 

My apologies...I failed to clarify before that the information above applies to the LAN settongs.

<rant>

I just got off of the phone with a support person that was all BUT helpful. At first he tried to insist that I needed to contact my ISP. Then when I started to get spitting mad he tried to tell me that even though the static IP reservation in question was on the same subnet as everything else that because it was not also in the dynamic IP pool it could not be used. I tried repeatedly to explain in terms that he could understand, I asked for a supervisor, I asked for someone who speaks Spanish, I begged to speak with someone else, but he would not...he just kept arguing.

I explained that I was a network engineer for 11 years and that I have had my home network configured exactly this same way throughout the history of several generations of routers over many years. It has always worked perfectly until I got THIS router. All I wanted was for the guy to submit a bug report!

I'm trying to decide now if I should just use OpenWRT, or just return the device and close the book on TP Link forever.

<\rant>

@VousDeux 

So, right about the time I posted the above reply the TP Link agent called me back to apologize and we proceeded to open an advanced support ticket. After the call ended I began gathering screenshots to add to the ticket when out of the blue it just started working. I know how this sounds, but I assure you I'm not just trying to avoid the embarrassment of having to admit my mistake. It was not cooperating...lol.

Yeah, so while I was in the process of giving my tablet a static address so I could connect to the misconfigured device and grab a screeshot showing the correct, statically assigned DHCP IP address with the incorrect subnet mask, I looked up to see that the troublesome yellow light had returned to its blue state.

At this point I cannot say for sure why I was having such a difficult time getting the device to cooperate, but I'm starting to think it might have been the access point device in question that was being so stubborn; in which case I do owe TP Link an apology for thinking it was their router that was at fault. In any case all is finally well on my end.

Thank you for your time

~Jerry

@Kevin_Z 

Yes. I have the A20 setup as the main gateway and DHCP server.  The 2.4 GHz WiFi is disabled on this device. Then I have a network switch connected to one of its LAN ports; which serves streaming devices and game consoles. Next I have another switch for things like VOIP, NAS, home automation and security devices. To this second switch is also where I have a mesh router with satellites running in AP mode. The second router serves 2.4 GHz only devices. Doing it this way allows me to distribute the network load across multiple CPUs and expands the range of the 2.4 GHz network to better serve some far-reaching home automation and security devices.

Edit: I guess I should also add that the ISP provided gateway is running in bridge mode. I have also toyed with the idea of setting up a VLAN for the home devices to add another layer of security, but for now the above is what I am doing.