Bug : temperature attribute must be a string

I have a custom driver implementing the temperature measurement capability which was showing up as "no response" when the device is exposed to Apple Home via the built-in Homekit Integration.

After some fiddling and comparing code to other custom drivers that worked, turns out the reason was that a float value was assigned to the temperature attribute by the driver. When I changed this value to a string, the temperature showed up correctly in Apple Home. Docs say temperature measurement capability has a temperature attribute type NUMBER...

Not seeing this behaviour with humidity, which shows up correctly and has an integer value assigned to the attribute... Something odd going on.