No not normal. Unscrewing is not normal. Not enough glue or you unscrewed it with enough force to overcome the glue. Probably you have now allowed a little more chance of a little more water ingress due to breaking the glue seal.
Now, then interestingly, we now know how they made it! (screw it tightly, probably with some glue).
I own the newer and older LC40. I use the newer LC40 where I am a frequent user as its easier to recharge, the original older LC40 I just stow around as emergency lights, but even that need has waned as I also got the Eufy stick-on lights in all the places in home we may be stumbling so we’re well covered now.
I am in last preparations for a 3 week off-grid with a newer Anker LC40, an Anker Powerport Solar 2, Powerport II 6700, and a 256GB storage phone stuffed with box-sets videos, and a pair of Anker Waterproof phone pouches. I am re-waterproofing my tent next week.