Wobble

Endurace CF SLX 8 Di2 Aero, less than 500 miles.

On a group ride yesterday, we were descending a long straight grade. I was doing about 38mph into an almost direct headwind. The bike started to wobble and vibrate, felt like I was losing control. I thought I had a flat so I quickly slowed, then stopped. No flat.

It didn't happen again on the ride.

I had this bike up to 42mph a few hundred miles ago with no issues. There's no obvious damage to the bike

The DT Swiss wheels really catch the wind and can pitch the bike sideways.

Has anyone experienced this? Could it be caused by the headwind?