GridBox Multilingual Store: Add to Cart Not Working

I created an e-commerce site with three languages: Italian (main language), English, and Spanish.
As per your instructions:
• I installed the three languages ​​in GridBox
• I created three different templates for each language
• I created three different app stores, associating them with the corresponding language template and associating them with the language
• I created three different checkouts associated with the language
Everything works, but when I try to add to the cart with the active language other than Italian, i.e., English or Spanish, it always says "cart is empty."
I'm attaching the animated gif of the problem.

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