Have you ever renamed a device or added a new device?

If the answer is "Yes":
For Amazon Alexa users: Please use the "discover my device" voice command to sync the device settings. Alternatively, you can refer to this FAQ to link the meross skill again.
For Google Assistant users: Google Assistant automatically refreshes its device list. You can unlink your meross account and then link it again through the Google Home app to manually start the device list refresh operation.

If the answer is "No":
Usually, this happens rarely. But when it happens, please perform the setup step again.
1. Reset your Amazon Echo or Google Home devices, then set them up again.
2. Unlink the meross skill and then link it.