Different API Ajax calls return always the same result

I have a strange problem using the Ajax API, in my page I call the suggest GET method multiple times to get a list of products searching its by sku.
I noticed that only my first call works well, all the following calls give me the same product retrieved by first call.

I exclude some code problem because this problem occurs only on live theme, in the development themes works all properly

Ex

https://mystore/search/suggest.json?q=XYZ&resources[type]=product&resources[options][unavailable_products]=hide&resources[options][fields]=variants.sku

live theme: return product A

dev theme: return product A

https://mystore/search/suggest.json?q=ABC&resources[type]=product&resources[options][unavailable_products]=hide&resources[options][fields]=variants.sku

live theme: return product A

dev theme: return product B

Could someone help me?

The problem seems to have solved itself.

But can someone explain to me what happened? Maybe there was some change or some problem in the shopify infrastructure, is it possible?