Help with Fenix LD10

I have recently noticed an issue with my LD10 regarding output modes. There seems to be little to no difference between the medium and high modes, and turbo mode is actually slightly dimmer than the regular high setting. I have noticed that putting in a fresh battery will remedy this problem, but only for a while. It doesn't seem to be linked with runtime so much, as I have noticed that it will be operating normally one day, and will not the next.

Some additional info here: The flashlight is not very old, just about six months. The battery terminals are clean. I am just using a Costco brand AA.

Any suggestions would be greatly appreciated. Thank you for your time.
-Sam

You need stronger alkaline batteries for longer run times (like duracell or eveready ). As your batteries drain, the higher levels of brightness will drop first, warning you to replace them. Save the cheap alkalines for low-power devices. I have a Fenix MC10 and the high level doesn't last very long with even the best alkalines. Rechargables in this case would be a good option.

Good to know, thanks a lot.

I wouldn't use an alkaline in the LD10 in high & turbo modes. An alkaline cell can not support such a high power draw.
Extreme power draws & overdischarge is what promotes leaks.