Google Home says, "I found multiple matching 'device types'. Can you try your request again?"
This error likely means that the action does not have the name of one of the devices in the device list.
For more information on naming devices, see Google Home does not understand the names of the devices.
Thermostats
Another reason for receiving the error message is if there are multiple thermostats and one of those thermostats is named thermostat. If there are multiple thermostats, be specific with the naming convention, such as Upstairs Thermostat and Downstairs Thermostat.