I just encountered this very issue as well… We have a page builder (Flexible Content) where each layout loads in a cloned component. A sync was performed (with all syncable fields checked), at which point it seems the page builder was “expanded” into its component fields…
BUT…
Not all of the fields were correct 🙁 At least one of the components was missing a field (and that field also wasn’t showing on the front-end). This is how we discovered there was an issue.
I noticed the mod date on the JSON of the page builder was way different from what it should have been and I assumed that someone had messed with it in the admin. I pulled a backup from the day before and that JSON file looked correct. I was able to update the timestamp on my local version of the JSON and pushed to the site, performed a sync, and the missing field(s) was restored.
