03-07-2019 12:26 PM
Hi @AT. Do you mean to say that the same concern happens even if your handheld device is connected to the Wi-Fi? What's the current LED status of your Wemo Switch? Based on the message prompted, it seems like your 4G doesn't have enough internet to access and control your Wemo Devices.
You can remotely control and manage your Wemo device to through Wemo App so long as the Remote Access is enabled. Make sure that you have a good connection with your devices, and you have installed the current version of your devices' firmware so as the Wemo App.
For isolation, try force closing the Wemo App, and power cycle your Wemo devices.