First fusion clip - can't play it in edit panel?

Did my first fusion clip which was just a tracker with text following the tracker.

I go back to my edit page and once it gets to the edit page, it's ultra laggy. I am using Dell XPS 15, i7 CPU, 32GB ram, GTX 1050. Every other clip is playing fine. I am using optimized media and I generated optimized media for the fusion clip too...

This makes it unusable. Is there a reason it's so sluggish AND won't cache?

On R15 final

Cache the Fusion clips.

Cache the Fusion clips.

I right clicked the fusion clip, render cache fusion output > on, played it in the timeline a few times... but it's still not smooth?

Cache the Fusion clips.

I right clicked the fusion clip, render cache fusion output > on, played it in the timeline a few times... but it's still not smooth?

is it [smart cache] on? (it should)

I observed the same issue.
No chance to get a smooth cached Fusion clip.

R15 final - 5820k - 16GB - 1080ti

-Heimo