What attribute priority are you using? Have you tried negative values?

I add this calculated attribute to the device and it doesn't generate the ignition event
Currently, the computed attribute is using priority 0 (default). I haven't tried negative values yet.
The computed attribute is configured as:
Attribute: ignition
Expression: null
Type: boolean
It is assigned only to the Seeworld R12L, and it seems to be working because the false ignition ON/OFF events are no longer being generated.
I will test it with a negative priority as you suggested. Would you recommend -1?
Any negative value.
I have ignored the ignition with a calculated attribute, so as not to continue receiving false ignition events currently being sent by the Seeworld R12L GPS.