Swimming pool thermometer - 433 MHz

Welcome to the community!

The temperature sensors are displayed inside the universal sensor device (hold to open in the mobile app).

The temperature sensor does need to be connected (mandatory) to the binary sensor before you include it into Homey.
So if all say a dash (-) then you probably included it into Homey before you connected the temperature sensor, or that extension cable is too long.
If this is the case you will have to remove it from Homey/reset the device by going either in the device’s settings, and click remove and follow the instructions, or go to more… -> settings -> z-wave -> remove device so it will reset the device internally (also why you got the message that it already was included) and remove it from Homey if it was there.