Thermostat temperature in Home app

Hi all.
Ok so I have a Hive home thermostat system connected to both my Apple Home and Amazon Alexa systems.
If the current temperature in the apartment is, for example, 20 degrees Celsius:
The Hive app will say it's 20 degrees.
My Amazon Echo / Alexa will say it's 20 degrees.
But the Home app on my iPhone, and Siri on the iPhone and HomePod, will say something like, "the temperature is ranging from 19.5 to 20.5 degrees". It always answers with a range, and refuses to tell me the exact current temperature, despite it being provided by the thermostat's system.
Do other people have this issue too? Is there anything I can do about it?
Cheers.