You can troubleshoot the following:
·If you paired the device with Home app,please add it again by Meross app.
·Check whether your home Wi-Fi is connected to the internet or not.
·Make sure the password of your home Wi-Fi hasn't been changed.
·Make sure your device is covered by your home Wi-Fi.Moving it closer to Wi-Fi router or install a Wi-Fi range extender would help.
·If all else fails,please factory reset your device and try to add it again.
Hold the power button for 5 seconds, it will reset and enter Wi-Fi configuration mode. Note that factory reset will erase all of your custom settings, and you'll have to set it up again.
Please visit https://www.meross.com/support/FAQ/230.html for solution.
You can tap "Don't Have a Code or Can't Scan" and input the setup code manually.
Please make sure your iOS is connecting to the 2.4GHz of your home Wi-Fi and you are having iOS 13 or later. Restart your iOS will help due to some system cache issue.