height_above_ground ignores scaffolding, in the attached screenshot, height_above_ground is referenced for the fall animation where the value is greater than 6 blocks above ground, but the scaffolding is clearly right below the player's legs.
The issue is partially fixed using is_on_ground to stop the animation when standing on the scaffolding.
I will also try to use the variable is_climbing in a minute and let you know.
@tight current