Hi,
exactly the same issue here.
WP: 5.1.1
ACF: 5.7.12
I was able to find there is a conflict with the following plugin:
https://wordpress.org/plugins/social-networks-auto-poster-facebook-twitter-g/
SNAP: 4.3.4
Save as draft or (update post like described in the original post) is working fine. Only the original publish option is not working correctly.
thanks for this nice plugin and hope you will be able to solve this issue.
Good luck.
