After Add to Cart, default WC product loads instead of customized

Good day,

WP 4.9.8, FPD Version 3.9.1 ,  WC 3.5.1

When a designed product is added in the cart it doesn’t show the Fancy Product Designer view for the customer to make further changes if needed, but shows the default Woocommerce product.

The Fancy Product Designer option "Add-To-Cart: Load... > customized product" is enabled.

Strange that it works with our current plugin WooSwatches – Woocommerce Color or Image Variation Swatches  - after adding to cart it displays the customer made product as intended and set in Fancy Product Designer settings.

I'd like to use another swatches plugin and when testing came across this issue. It happens also with setup of just Woocommerce, default theme, and FPD. Happens also with several versions upto latest of FPD.

Please check the vid - in first part shows the wrong behaviour after Add to Cart button, in second with the other plugin - the right behaviour as per setting in FPD admin:
https://drive.google.com/file/d/1dB2nuTsoQW6zApENMKIxPUF5eax7ERqV/view

Here is also a vid from other support that demonstrates the wrong behaviour:
https://www.useloom.com/share/6dd358dde46d4997a5e59ed00bf35b6d

Regards!