Change the ProductType don't change ProductTemplateId

Hi, I'm using the API Plugin to update a product and changing some product type from Grouped with associated product to simple with attributes and attributtes combinations. So far so good, but when I go to the product detail page on the store, the template don't update and show a product out of stock. I check the database and the column ProductTemplateId doesn't update, but if I click on save button on the admin area fix the problem

Maybe something to do with cache ?
Use your plugin to change the value.
Then clear the cache and see what happens

I already tried it.

The problem is that the column ProductTemplateId doesn't change even as I change the product type.

They are seperate fields - not linked and you should be able to save them.

So to confirm you sent the ProductTypeId and ProductTemplateId to a different value. You check the database record and only the ProductTypeId is saved ?

Make sure you check the database itself because there is another field in ProductTemplate called IgnoredProductTypes which will affect the display of values in the Admin