nikwitting

Problem solved.
After some time i found the term “deeplinking lightbox” to be useful in my search. Most deeplinking lightboxes allows you to acces the open lightbox with a link but still the back button did either go to far back or did not close the lightbox at all. I then found this useful site comparing lightboxes, with a demo for each:
https://justifiedgrid.com/lightboxes/
I tested them all and found the PhotoSwipe lightbox to be the only one with the right functionality such that the back button actually closes the lightbox as intended while staying in the same page.

From WordPress i then added the plugin named “Lightbox with PhotoSwipe”
And to allow it to work on the woocommerce product images I disabled the standard lightbox by adding the following to functions.php:

add_action( 'wp', 'tu_disable_wc_lightbox', 20 );
function tu_disable_wc_lightbox() {
    remove_theme_support( 'wc-product-gallery-lightbox' );
}

Quite surprises that I only found this single plugin among many with this quite basic but effective functionality.