HVAC mode in home assistant

[samusamu81]

Hello,
can somebody explain me how the "auto" feature works when I use home assistant?

Let's assume it's cold in the house.
If I set the unit to work in auto mode (either from the physical controller or from home assistant) the unit will start heating, as it should.
The phisical controller will display "auto/heat" Home assistant will display "heat".

I don't know if this is a bug or by design. If it is by design, is there any code I can read to know the unit is in auto mode and not in heating mode?
Thanks