Hello,
If the problem is independent of the theme, it means that we as theme support can’t help.
What recommendations were given by WPML support? Make sure you followed them.
When you create a completely new product do you have the same problem?
Try to disable all the third-party plugins (including cache plugins), that does not come bundled with XStore https://xstore.helpscoutdocs.com/article/36-included-plugins , clear the cache of the browser, and check then. Maybe one of the additional plugins is the reason for the problem.
Regards