Is my new Nitecore E4K faulty?

[Distorted Vision]

I just received a Nitecore E4K which I bought from AliExpress.

I can't get it to stay in Turbo brightness setting. It seems to be switching down to low setting. I fully charged the battery before using it.

 

[Hooked on Fenix]

Read the instructions. Triple tap will keep it on turbo (or strobe depending how you set it up). Turbo only lasts 20-25 seconds before dropping down to prevent overheating. Holding down the button while on will bump it up to turbo and keep it on turbo only as long as you hold it down. Hold the button while off to cycle up through settings up to turbo, then release when you're at the brightness you want. You have three ways to access turbo. Two ways stay on until light gets too hot, one way is temporary. This light has a complicated user interface. Once you get used to it, it's not bad. Read the manual and practice the features for a few minutes before taking it out in the dark.