Calculated attribute alarms are not working for me

Joystick17 days ago

@Andres Petrillo
Thanks, this sort of cleared it up for me as well. Just need to confirm below.
I have a computed attribute linked to my main group and have teltonika and meitrack devices in the same group.
Teltonika devices include ignition flag in messages but for meitrack devices I use computed attribute to flag it for various reasons.
Using example 1 makes ignition flag for teltonika device disappear but example 2 work. Have I done it correctly?

Example 1
Attribute: ignition
Expression: protocol=="meitrack"?power?power>="10":null:null

Example 2
Attribute: ignition
protocol=="meitrack"?power?power>="10":null:(ignition?ignition:null)

Thanks for the help