Solution for this, The hook name can only contain numbers, letters, dashes, periods and underscores.
…The hook name can only contain numbers, letters, dashes, periods and underscores. hooks.min.js:1:1495
Resulting the ACF repeater won’ t save the content. Any solution?
1- After a long time investigating it looks like ACF(Avanced Custom Field), or/and ACF Repeater & Flexible Content Collapser is not working on the WordPress Version 5.0.2.
The urgent and quick solution for me was going back the previous version of WordPress.