Hi there,
Thanks for posting in.
There are known issues between Pro/X and WPML so let’s try this as work around.
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In your WPML URL setting, make sure it’s in this format /en/ instead of ?lang=en. I think it’s in language settings section of your WPML.
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Then go to Admin > Settings > Permalinks and save it (to flush it).
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Then, go to your header builder manually by accessing the URL in your browser
Examples,
http://example.com/en/x/
http://example.com/fr/x/
- Then create your header for that language as well your preferred contents.
This works on my test, but may not in your install. Please provide your admin login credentials so I could try it too 
Thanks!