@D. Tengler Thank you for your response and I am sorry if I wasn't a good explainer. When I close the "Added to cart" confirmation modal, a request is sent to the ProductController, as above (my post). That changes the URL with a product URL, and refreshes every product miniature.
This never happened until today.
I am not able to find the AJAX that is activated on modal closing that could send that request.
As tested on PS 1.7 demo, when closing the confirmation modal it just dissapears, no GET request is made to ProductController.