Hi,

I have a mix of Kasa and Tapo devices, all set up using the Android Tapo App (v3.18.506).

My Wi-Fi is split into two distinct networks: a dedicated 2.4 GHz IoT network and a dedicated 5 GHz network. All smart devices live on the 2.4 GHz IoT network, and my Android phone usually connects to the 5 GHz network. Dedicated apps for my non-TP-Link smart devices continue to work perfectly when my phone is on the 5 GHz band. All of my devices are also linked to Amazon Alexa and can be controlled from there without issue.

However, a few weeks ago, a problem started. When my Android phone is connected to the 5 GHz network, the Tapo App shows all Tapo devices as offline, while all Kasa devices remain online.

As this setup has worked flawlessly for years, I wonder why the Tapo App suddenly only communicates with Tapo devices when the phone is forced onto the 2.4 GHz IoT network.

Additional Technical Details:

• Network Isolation: The 2.4 GHz IoT network and 5 GHz network are isolated on separate VLANs with an mDNS Proxy active between them.
• Device Agnostic: This issue is happening identically across three different Android devices (phones and tablets) running different Android OS versions. All of them used to work perfectly on the 5 GHz network.
• Crucial Cloud Clue: If I turn off Wi-Fi on any of these devices and use Mobile Data, all Tapo devices immediately show as Online and work perfectly via cloud control.
• The Root Issue: The "Offline" issue only happens when a wireless device is on the 5 GHz VLAN, suggesting the Tapo app is failing to fall back to cloud control when cross-VLAN local discovery fails, whereas Kasa devices handle this fallback seamlessly.

I would appreciate any suggestions or insights into this issue.

Regards,

Steen