Hi @ule. I can confirm that the devices do not show up as UPNP devices, and yes, I can see other UPNP devices on the network.
Walmart sells these as the “WorkChoice 1 Ol Wi-Fi Indoor Switch, White.” The model number from the manufacturer’s web site, and on the back of my devices, is the same (CT-065W), and the description mentions the “ECO plug” app. I have a few coming in the mail, so I’ll confirm when they arrive.