lighting – Why did my Yongnuo YN685 flash stop working after turning it off from the camera?

In the middle of a session, I had the idea of ​​taking some pictures with flash off camera. This is the equipment I used:

  • camera: Nikon D7100
  • Speed ​​of light: Yongnuo YN685
  • radio trigger Yongnuo YN622 TX-N

I realized that I had forgotten the flash support in another room. So I managed to balance it on the ground. My idea was to do some effect with a colored gel behind my theme. The radio trigger fired the flash.

But later, when I tried to put the flash back on top of the camera, it did not turn on. I had new batteries, but it did not turn on at all. I did not smell any burning. Did I make a mistake while shooting him while he was on the ground?