If your samples are stored in a box at room temperature out of direct light, they are not improperly stored. I have bottles of perfume that are about 10 years old and have been stored in their original box in a dresser drawer for ten years, and they smell the same as they always have.
I don't think it's the juice that's changed, especially if they've been in the box only a few months. It could be they smell different to you because the weather has changed, or your appreciation of scents has changed. There are some rich, resinous fragrances that are too lush to wear in warm, summer weather (even though I love them); and some delightful, lightweight florals that seem completely ridiculous to me when it's 40ºF and raining outside. And sometimes I'm just not in the mood for something, and that might last for a while, before I fall in love with it all over again.
And I nearly forgot-- Welcome to Basenotes, Islands! :wave: