Missing Meta Keys on WooCommerce orders

I have a WPML problem with order language being ignored, and according to WPML it is because there is no meta keys in the metabox on orders. I only see attributes. Especially wpml_languages are missing.

I have a fresh install with the same theme, the same WP version and the same plugins – here I do not have this problem.

I have 3 sites from the same DB copy, one local, one for testing and one live. Everyone has this problem.

Have tried switching to a default theme, disabling all plugins, updating everything, etc. Nothing helps.

Any idea what could be causing this?