EAN code not changing on frontpage on different combinations

[Webinventors]

Greetings!

I have a small problem with my prestashop website.
I have a lot of different products with different combinations. The problem is whenever I change the combination (size) on the frontpage, it will not change the EAN code in the URL and neither on the front page. The reference code does change on the URL and frontpage for different combinations. I tried switching to default theme to see if this problem still occurrs, and it does.

Link to my website and an example product: https://www.dekbeddengoed.nl/sleeptime-dekbedden/4125-sleeptime-3d-air-micro-touch-mono-dekbed-8719242011508.html#/46-materiaal-micropercal/28-formaat-140_x_220_cm

It's a huge problem for me at the moment because multiple affiliate site's require a valid EAN code for every attribute or combination.

Any help would be appreciated, thanks in advance.
Enclosed are two pictures to make the problem more clear and to show my URL rewrite settings at the moment.
Note: this problem hasn't always been around. I don't know since when this problem occured.

Greetings!