Vincero Men's Kairos Opportunity Pendant in Sterling Silver on Wax Cord

I love my Kairos But... There have been a couple of times when my pendant has somehow become unwound and momentarily lost. I've looked in the mirror, or felt around my neck, and it was gone. Luckily, once I found it on the floor at work, and another time I found it on my front porch, but I'm trying to figure out how this happens... I don't want to lose it permanently and I've seen another review where somebody has lost it leaving only the necklace part...