Homekit device access distance

Dear all,

My HomeKit devices stop working remotely.

My setup is Apple TV HD + HomePod mini in the first flour

Eve energy socket on the second flour. This device on this place stop worked.

Wi-Fi is available on both locations. Physical distance from pod or TV to the socket is few meters 4-6+-

I am also surprised when my mobile is in the location (also with disabled BT, Wifi ) everything is working

But when I leave this location it device is not manageable

What is the communication interface with HomeKit devices (nfc that cannot be managed by user?) because everything other can be put disabled by user .

Or Disable option is not real disable in iPhone and this phone still communicating on the backend to each other.

Please explain architecture of homekit and how I can extend range of signal for cover whole house with good signal.