Strange behaviour in status menu

I have an obd tracker that uses the protocol eelink and I'm noticing a strange behaviour in the status menu.
When the car is turned off in the status menu I see Ignition=no and Blocked=no but when the car is turned on these voices (Ignition and Blocked) disappear from the status menu. Why this happens?

If attributes disappear it means that your device doesn't report them.

Is there some way to exclude these voices from the status menu?

Exclude? Voices?

Yes, is there a way to remove from the status menu these entries that disappear because the device doesn't report them.

It's possible to hide position attributes. There is an option for it in user settings (in user attributes).