I want to Update the Firmware of my Decos in order to fix the security warnings from the newer IOs 14 devices.

I have a Tp-Link MR600 4g router (with wifi turned off) in my attic with an ethernet cable directly to my primary Deco M9 Plus v2, then I have ethernet backhaul to the other two Deco M9s. I have the IOS app v 2.9.6 that tells me all Decos are online and updated. I have downloaded the "M9Plus_2.0_upgrade_tool_v1.2.0_macOS.zip" file to my Mac computer which is on both the same ethernet and Deco-wifi net as all the Decos. I log into the update assistant with my TP link ID, the same ID as for the Deco app (and my ID for the Tether app for the TP link router), but I can not get past the "Case one" as shown here: 

https://www.tp-link.com/en/support/faq/2930/

I have no VPN or virtual adaptors. My ethernet setup includes an apple time capsule and some ethernet switches but it is all one common network so visibilty of the Main Deco should  be clear. I have tried just pure Wifi with no ethernet in order to just see the Primary Deco but that does not help. Any ideas?....