magento2 – Can not save the list of my products after editing, error: "The product does not exist", was discovered due to OOS related products. But why?

My product list could not be saved after editing, error message "The product does not exist", The cause is due to the fact that related products are OOS products. But why does this affect the list of main products?

Would like to know if there is a Magento logic or bug that needs to be fixed.

Thanks in advance and any help welcomed!