List duplicate items external collection

I’m using the google sheet and apps script sheet to create the API the result is fine no issue but when i using in the list i got duplicate the function for API GET

its getting one but not all

can you explain more

the Api should be get all

i guess you used get one

nio. i used GET ALL
and in the results for testing API it’s showing the correct data

so what is the issue

the issue when linked with list the items is duplicate in list as the picture i was attached