Indeed!It's a shitty wheelset.
I had this problem as well. I found my hub's end caps were too tight. I used cone wrenches to loosen the caps, then I tightened them up finger tight only, and then backed off slightly. The wheel now spins free.Bigger concern... above about 25mph, the drag on the freehub is enough to drop chain tension when coasting, making for some scary clunks at high speed and general chain instability.
I've decided to get an EIE (ChiCarbon) set with DT Swiss hubs. Now I just have see if the WTB wheelset will hold up for the 3 or 4 more weeks it's going to take to get it.I'm always searching for that magic gravel wheelset... But these do the job.