Bench Restore version-12

I am in a way of upgrading my customer sites from 12 to 13.

I do some test in my laptop.

  1. install erpnext v12. versions are (bench version)
    erpnext 12.31.0
    frappe 12.28.2
    customapp 1.0.0

  2. restoring my customer database :
    bench restore database.sql.gz
    Then I’ve got this message:

Your site will be downgraded from Frappe 13.41.4 to 12.28.2

Strange cause my site is having v12 of frappe , right?
I try to continue and the restore goes whiteout error msg.

but when I accessed it gives me
No module named ‘frappe.core.doctype.shopping_cart_settings’

It may not be related actually.
My question is why the system says that my frappe will be downgraded from 13 to 12 since I am
sure I am not installing any frappe version 13 on the site?

thanks and regards