Handheld AR - Detect image tracking lost and despawn actor?

I’m working on a basic AR program right now and I’ve run into a wall with tracking. Currently I have a basic blueprint that is detecting a candidate image, and spawning an actor. There are multiple images, and in this blueprint I want to track a specific shape based on a specific image. Here’s a sample of it.
I’m aware that checking the display name of the tracked image isn’t the best way to identify it, but I didn’t know any other way.

what I need is **​​​​​​​when the candidate image is no longer tracked (either at all or for an arbitrary number of seconds), the actor despawns. **I currently can’t figure out a way to tell if the image is actively being tracked, because my blueprint sees the image once and throws a cube/cone up on screen. Please give some tips!