It seems like there are 2 things which are causing WPML issues. I will write up a guide in the docs to help future users:
1. The “Field Groups” must be enabled for translation, and a field group must exist for each language.
2. When editing a post, make sure all custom fields in the ‘Multilingual Content Setup’ metabox are set to ‘Translate’ and not ‘Copy’, otherwise the values will not be updated.
Hope his helps,
All WPML tests seems to be working great on my end.
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