@MikeLieberman 

I would reset the router to factory default settings by pressing and holding the small "Reset" button on the back of the router (hold until all LEDs turn on momentarily) and then check if the "Firmware Upgrade" menu appears after that.

  @woozle Thanks.

It was really just that as the Net Admin I was accessing this from the WAN side. I brought the unit to my office and accessed the LAN side. All work fine once I found the EU version of the firmware. 

  @woozle , This is not for you... but it is a complaint about the tp-link websites. So I am just venting I guess.

Maybe if you live in the EU, or UK or the USA, and even though it doesn't query about those things, and only asks for the version number the websites work for you, but I am in the Philippines and the tp-link site absolutely does not work for us. If I by something made by tp-link, it might come from anywhere in the world. The Philippines site doesn't even mention my unit even though I bought is locally at a shop is a mall. I found 'version 4' firmware on the US site and tried loading it. It failed essentially saying I had the wrong file. It was then that I notices that I had used: 

Archer_C20v4_US_0.9.1_4.16_up_boot[190103-rel53059].bin

But the router's label said EU. I looked for a EU site for tp-link and there was one but initially the site I was looking at didn't have my firmware, Then I did a web search for:
Archer_C20v4_EU_0.9.1_4.16_up_boot[190103-rel53059].bin

And I located it. That worked. Pure frustration! On no site do they ask 'region' in selecting the right file to download. 

So for clarity I am in General Santos City Philippines. This is what the label on my C20 says: