Not sure how we should go about that. WPML is tied to hockeyshop.dk (main language) and hockeyproshop.de (second language). Kinsta only provides one URL, so not sure how you can access the german (.de) products.
Can you configure WPML to only use one domain for the staging-site?
And trying multiple things to replicate the issue, but I am unable too. I will keep monitoring.
Further, when I disabled all plugins, the site resulted in a fatal error, so to fix this I would need ftp details as well as the previous login details is removed due to some issues, so can you provide the details again in the next private reply.