I get a message “Device was not found”

Move your speaker closer to your wireless router.

Your speakers and controller device may not be on the same network. Verify that the controller device is on the same network as your speakers. This is usually configured under the Settings feature on your device.
If you have more than one network, your device may hop to a different network as you move around your home.

Make sure you don’t have any other electronic devices interfering with your wireless network signals. Microwave ovens, cordless phones, and some televisions can cause wireless network interference.

If your speakers are located far away from your router, consider adding a Wireless Range Extender like the HEOS Extend.

In case your wireless router is incompatible with HEOS speaker, please use the optional HEOS Extend Wireless Range Extender and hard-wire it to your router.