Klarus XT21X not working

Considering the battery doesn't last 5 hours on the level you had it on, I'd say you overdrained the battery and your tester is faulty. Try a different battery in the light. If it works, it's the battery. If it doesn't, it's the light that failed. Did you use an unprotected battery in the light?

It was the factory battery after cutting the klarus wrapper off I seen is was a Samsung INR21700-50E. I put the only battery I have in the light a 18650 LG hg2 and put a perfect size of aluminum foil take up the space and it works fine and even charges the battery. I know my tester is not faulty it is a professional grade fluke multi-meter I'm an electrician so I needed the best tester I could buy. Klarus said the battery is covered under the warranty and will send me a replacement.they said the protection circuit failed.