You can redo setup process to fix it.
The smart hub can support up to 16 smart thermostats. You can set up multiple hubs to manage dozens of smart thermostats.
The setup includes hardware installation and software installation. We recommend you to use meross app to set up. In meross app, you will enjoy crystal clear step-by-step instructions, connector compatibility guide, dedicated troubleshooting, tips for use, and firmware upgrade notice. You can only set up HomeKit in meross app, but you will be able to manage your thermostat in both meross app and Apple Home app.