A firework rocket from the creative inventory doesn't show a flight duration

The Bug

I am unsure if this is intended or not, but it is inconsistent with other firework rockets, so I thought I would make a post.

Reproduce

1. Open the creative inventory.
2. Locate the firework rocket.

Observed Behavior

Firework rockets obtained from the creative inventory do not display their flight duration.

Expected Behavior

Firework rockets obtained from the creative inventory would display their flight duration.