i've recently purchased a cocktail kingdom koriko shaker, but when trying to use it i've found that it doesn't seal as well as other boston shakers i've used. both the cheap amazon shaker and the various tin on tin shakers and tin on glass shakers at my workplace seam to seal far better. i'm not sure if i need to use the koriko differently but it has repeatedly started breaking the seal on its own when shaking with ice, which may also happen with others but never this consistently.

i'm just wondering if maybe my technique is wrong or if i just received a dud product because this doesn't feel like the high quality piece of equipment that people are raving about