[Cerrado] WooCommerce product variations in English disappearing over time

Background of the issue:
I am running a WooCommerce store created with Elementor, using WPML for translations. Each product has several variations (e.g., size, quantity), which are correctly synchronized to the English version using the WooCommerce Multilingual plugin. Initially, the variations are visible and selectable on the English product pages. Link to a page where the issue can be seen: English: enlace oculto Correct German product: enlace oculto

Symptoms:
After some hours or days, the variations on the English version start disappearing from the frontend – not all at once, but gradually. In the backend, the variations are no longer linked to the original German product variations.

Questions:
Why are the product variations on the English version disappearing over time?
How can I ensure that the product variations remain visible and linked correctly?