Still no answer? This puzzles me, support was always great with ACF Pro.
WPML has released a minor update to address this issue. It did so, partly. We get no longer that JSON-like stuff and the “Array array” output.
But: Changing fields in one language messes up fields in another language. I’m not sure what role ACF or the bridge plugin plays in that regard, but it’s a complete mess, a nightmare so to speak.
I’m really reaching out to the ACF team for some insight on this.
Cheers.