I have a mesh network consisting of three Deco M9 Plus V2 devices and one Deco M9 Plus V1 device. The firmware of the V2 devices are all up-to-date, but the V2 device is still at 1.4.3. When I tap the "Update Deco" option under "More" > "Router Settings" in the iOS app, it reports this older version as up-to-date. My V2s had this problem for some time before I discovered the update utility, but I understand that this utility only works for V2 devices. After using that utility previously, I was able to update the V2 devices to 1.5.1 recently through the iOS app (which is partly why it's odd that the app reports version 1.4.3 from the V1 Deco as though it applies to all my units). I did also attempt to access my V1 unit by entering its IP address in my web browser, but that didn't work. It might make a difference that the V1 unit is connected to the network through Ethernet backhaul since it is physically remote from the other Deco devices. It seems that maybe TP-Link did not envision a mixed-device network of V1 and V2 Deco M9 Plus units?
Bottom line, how do I update the V1 device's firmware in this scenario?