Thanks John. I will contact them about it. This plugin hasn’t been updated since a year now. Maybe they have not added support for it.
For now I will use this instead – a modified version of the sync json acf plugin.
https://gist.github.com/amjad/0d8bd7e9108001defc5fed546787a17b
Only major down side of this is that it creates the fields in the database for each sub site which is what we are trying to avoid for performance reasons.
