You have one of those “moving sand art” (some are made by Exotic Sands) – and they “lose” water and stop working?
The NJroute22.com VLOG of the day is a short video on how to fix.
Don’t feel like watching?
Get a 0.8mm thick syringe that is longer than 40mm.
Some distilled water and food coloring.
Inject water into the frame.
Seal (if necessary) with silicone or similar adhesive / sealant.