Why does Google keep disapproving my custom products due to GTIN numbers?

Hello need advise on this i keep getting messages on my google feed to add my gtin or mpn.

All the products i have added on to my store are set as custom with the identifier as false but for some reason google keeps disapproving my products stating they have GTIN numbers. How do i solve this problem as i have made all products custom and selected identifier as false and done all i can to resolve this but i keep facing this problem. Any advise on how to resolve this cause i have done all i can to the best of my knowledge.

Secondly i have tried finding the GTIN number for these products but i never see them as i always get the products from aliexpress.

Will patiently wait for a reply. Thank you

What is the exact error Google Merchant Center is giving? Have you given a few hours to update? On a product that is having an issue, inside Merchant Center, find the product then view. Look at what attributes are in it and share it here so we can see.

There are a variety of GTIN related errors that can occur. Some being incorrect values, others being suggestions to provide them to help performance, and more.

hello please see image below i have made all products custom and set its identifiers as false but i still face this problem. How do i resolve this please?