Whatever they did, it didn't work. Maybe we are over-custimizing it but it is not unheard of to use ACF with multiple other plugins such as WP Code and custom scripts.
If you can share the problem you are experiencing on Making WordPress Slack (#secure-custom-fields channel), I'm sure relevant people would love to help out ASAP.
I work at Automattic and I can get you in touch with people from WordPress.org if that's easier. You can email me at batuhan@a8c.com.
If there are any bugs, regressions or any issues with the fork, it's in the interest of everyone to quickly find and resolve them, so I'm sure your help would be appreciated.
If I were an employee of A8C I wouldn't be touching this code with a ten foot pole - employees can still be found guilty of criminal wrongdoing even if their employer told them to do something.