"Acquire combat vehicle near The Seal" is not tracking

The exploration challenge says "Acquire combat vehicle near The Seal". 

This is my last incomplete exploration challenge (so I know what I am doing). I've spent the last 2 weeks focused on nothing but this challenge alone.

There are 3 vehicle spawn trailers around The Seal (2 are where the minimap still says "The Seal" at the bottom, 1 is adjacent to it between The Seal and Radar site)

I've completed missions, acquired vehicle cards, and opened the vehicle trailers at all 3. Many times (2 weeks worth of games). Over and over and over.