after import products in Odoo 17 the size of the product grid table is:

colspan="4" rowspan="4" class="oe_product" data-name="Product"

When i edit in customize Product size: set colspan=1 and rowspan=1. 

There will be 4 products on one row.

Very nice this works

When i make an upgrade on my products import template (with product id).

The colspan and rowspan are reset to 4 again.

Received the final answer from support.

The value from export = website_size_x and website_size_y

For import excel sheet : Size X and Size Y = both 1

(newbie problem)