There's a noise in my GAS IT bottle
The GAS IT bottle has moving parts inside them which will move on the top of the liquid LPG in the bottle so when a partly filled bottle is present and you move the bottle around, you might hear the items moving about inside the bottle. ( see picture below of the 80% auto shut off valve)
These moving items include the float on the end of the automatic shut off valve and also the float on the gas level indicator, which in turn moves a rod up and down in the brass fitting to tell the outside gas level indicator the gas level, so when the liquid LPG in the bottle is sloshing around then the floats on the valves will be riding up and down on these LPG waves as they are designed to do.
There isn't a safety issue, its very normal and won't affect the bottle in anyway.