license is granted even if reference date is in the past

Problem/Motivation

the license is set to "active" even if the reference date is in the past.

Steps to reproduce

create a product with a license based on a reference date in the past.
e.g one week ago and set interval to e.g. one day.

if the user buys the product, the license is active starting from current date, not the reference date in the product/license.
and the interval starts from date of purchase.

for testing, you can just create a license from admin backend and look at the details

Proposed resolution

use the reference date from product license, not date of purchase.