Recently I noticed that the freehub on my Zipp 303 NSW wheel is not engaging as quickly as expected, often taking about 90 degrees of crank rotation before anything happens. I've already pulled the cassette and cassette body off the have a look, but can't find anything obvious that is wrong. The wheelset is about 6 months old and I've only ridden about 1500km on it. Some time ago I did ride through a torrential storm, but I've never had any issues with other wheels before doing that. Does anyone have an idea what could be wrong with it before I go through the lengthy process of sending the wheel back to Germany?

Edit: I've recorded a short video showing the issue: