Notifier 3030 false fire alarm "magnet test"

[Newbie2023]

Hi everyone, False fire alarm 3 different days, each time it's different heat detector from the same loop card.

Checked panel history and indicate "magnet test". Devices seem to be fine. no troubles on this loop prior to false fire alarm.

what would cause this issue? bad heat detectors or loop card issue/cpu?

Any input would be greatly appreciate it.