Yes, it’s supposed to. I have a Shark and this is the weakest part of design. They never seat well and sand can leak out, so I usually leave it on when done, point up, then turn off. I have made a flap by cutting to size from lightweight thin plastic and duck tape into place.

Make sure a clear ultraviolet filter is not screwed on the end of the lens. Often dust will be trapped between the filter and the lens. Look at the side of the filter (if there) and you should see markings indicating size ( example 72mm), brand, and type. These filters can become very tight, but never use any tool to try to remove. Grip with cloth or rubber tipped gloves to remove. if no filter is screwed on the lens, and you see dust inside, that is a job for a camera repair specialist.