Hi James! Jaswinder and myself are from the same team.
We are using WooCommerce, all caching is disabled both on the site and the server.
Page builder we are using is Oxygen builder.
WPML is used for multilanguage & multicurrency.
All plugins are up to date, as it the core as well.
If required, I can set up a staging environment with the current situation and provide you with the logins.