Waypoint Gimbal Pitch

I have a simple 2 waypoint mission. Each waypoint has a different gimbal pitch and with pitch set to interpolate. I would expect the gimbal pitch to change properly from waypoint to waypoint but it does not seem to be working that way. Any idea why?

The gimbal vertical angel will gradually change from whatever the current angle at WP1 is to the set angle at WP2 whilst flying from WP1 to WP2.

If you want the gimbal to reach the set pitch at WP1, you need to insert a WP before WP1.
In a Straight Lines mission you can add an action ‘Tilt Camera’ at any Waypoint

Interpolate needs 2 Waypoints to work.