Dargyn and thumper disappear but player still in vehicle fly mode, and some squad mates cannot see thumper.

[Crossnub]

I was flying in a Dargyn attacking the Thumper's weak points when it suddenly disappeared and I blinked to someplace under the map nearby the Thumper. At the same time a squadmate could suddenly no longer see the thumper, only the smoke coming from it. 

 

I was still able to fly around, but the Dargyn itself was gone and I was back to attacking with my Warframe's equipment. I could also walk through the world, and back under it, the only way I found out how to reverse the problem was to launch my Archwing.