Can’t properly add new Smart Device

I recently purchased a new smart device to add to my home which already contains many (properly functioning) devices. This one is an Eve Smart Plug. (I already have other Eve switches working fine.) My HomePod is the hub for my home and I use the Home app on iPhone, iPad Pro, and MacBook Pro. I attempted to add the new Eve Smart Plug using the apps on my iPad Pro, scanning the QR code that came with the product. I tried many times, sometimes using the Eve app and sometimes using the Apple Home app. All attempts failed to pair. Then I tried my iPhone. Pairing worked easily. I was able to assign the device to Family Room, rename the device, and group the device with another light that I want to turn on and off together. From iPhone, everything works just as it should.

However, on iPad and MacBook, Home and Eve apps acknowledge that the device exists, showing it by the new name and in the right room and even grouped with the other device, but they can’t control the device at all. Both apps say “No Response” for this device. This also impacts Siri voice control. When I tell Siri to turn the device on or off, it also says the device is not responding. All other devices in Home work fine with Siri voice commands.

I’ve tried rebooting everything, deleting the device and installing it again (same problem - can only add with iPhone), and temporarily switching my WiFi to an older protocol. Contacted Eve support but no response yet.

Any ideas?