A product in Odoo is two things:  a product.template record and a product.product record.

Make sure you and your script knows why and when the script should be updating one versus the other.

Hello everyone,

I have the same problem

But I noticed that I can update only through the same module I used to insert the products for the first time, It seems that it is a validation between different modules to overcome duplicate External ID

Example:

I imported the products firstly through the  invoicing module /Sales/Sellable products

so when updating these products I have to import from the same path

I hope this might help

I am also experiencing this same issue. I will update as soon as I find some solution.