jetbeam 3m issues

Hello all, I just purchased a Jetbeam 3M XML about a month and a half ago and the light worked fine on the 18650 i had in it until i took it out to use in another light. Now when i put the cell in on and when the light is in head tightened max mode it come on for a few seconds and cuts off but if i turn the head to the user defined mode it works great even if its at the brightest setting. Ive used brand new out of the mailbox fully charged cells in this light and it did the same thing. I also noticed the retaining ring around the clicky was loose so i tightened that up and it worked fine, but its gone back to doing the same thing again. Any help would be great thanks.