Sorry for the inconvenience. We will definitely help you resolve the issue. Few simple troubleshooting steps might help us to pinpoint the issue:
1. Tighten the tail cap plate. I attached an image to show you how to do it. The light in image is a different model but the concept and method are the same.
2. Fully charge the battery until the blue indicator turns to constant on.
Keep us updated on the result. We will proceed accordingly.
