I am working on setting up WPML and till now with success. However, there is an issue I am running into. Both the main website and the other domain (WPML's domain per language option) work. But, as soon as I login to /wp-admin/, the URL changes to the WPML/English domain.
I have had this problem before, and I have fixed it by putting define-url rules in my wp-config file to the main domain. However, for some reason the URL is reverted back and the rules do not work anymore. Attached are two screenshots.
What is causing this and how can I let both URL's be the main/.nl domain?