UPDATE!
-Here are the screen captures of my setup and how it works. The above post is correct on how you approach doing a chest system. I will leave my original comment to show my progression. Basically my problem with multiple items came from not setting the construction script on the item itself. Everything works just like the inventory on the character but in the chest and I can have multiple items stored and retrieved no issue, like a real chest!
If you get stuck I would recommend walking away for a little bit and thinking about it. that’s how I figured it out. I hope my images guide you in the right path.