Resolved in: 1.9.0
Overview of the issue
Users using ACF Repeater Fields set to display on Options pages may find that an option added in one language is not automatically added to the other languages for translation. Instead, you have to add the translated settings separately.
Our development team is working to provide a workaround and a permanent resolution for this issue. For now, this feature is not supported in ACFML v1.8.0.