Background of the issue:
I am trying to add multiple different products to the cart using WPML. When I add a single product, it works as expected. However, when I add multiple different products, the second product initially appears in the cart but disappears after a page refresh. If I add the same product twice, it remains in the cart. Disabling WPML resolves the issue, confirming it as the cause. Link to a page where the issue can be seen: hidden link
Symptoms:
The second product disappears from the cart after a page refresh when multiple different products are added. The issue does not occur when the same product is added twice.
Questions:
Why does the second product disappear from the cart after a page refresh when using WPML?
How can I resolve the issue of products disappearing from the cart without disabling WPML?