Hi,

In the invoice the product field in the invoice line is not a required field. That is we have to select the product only if we need. The required field is the Description field, which is printed in the invoice.

If you want to add the product field into invoice you can inherit the report template add this field.

For inheriting the report template check out this tutorial : https://www.odoo.yenthevg.com/inheriting-and-modifying-qweb-reports/

And regarding the issues you have mentioned, if you are  thinking that these issues are by default(make sure that you can trace it in runbot ), then you can report it at https://github.com/odoo/odoo/issues

Thanks

Thanks. How can I inherit the report template please?