I am also seeing this issue.
I created a ‘Messages’ Field Group, into which I created two fields, and Location is configured with the following Rule:
[Post Category] [is equal to] [Messages]
While creating the Post, I see the Advanced Custom Fields’ ‘Messages’ Field Group as soon as I assign the ‘Messages’ category. And, while the Edit Post page is loading, I also see the ‘Messages’ Field Group. But as soon as the page loads, the Divi Builder loads, and the ‘Messages’ Field Group disappears.
Switching the Location from
[Post Category] [is equal to] [Messages]
to
[post_type] [is equal to] [post]
re-enables the ACF ‘Messages’ Field Group again.
