Bumping an older topic, but I am also having this issue. This solution to add pagination to a repeater field was previously recommended on the ACF forums. I would really like to get it working again. I believe I’ve had this issue since the WordPress 5.5 update, as I was already using php 7.3 when I first implemented this.
Post here: https://support.advancedcustomfields.com/forums/topic/advanced-field-repeater-pagination-with-custom-post/
https://jonathannicol.com/blog/2014/03/06/paginating-an-advanced-custom-fields-repeater/
Thanks so much! The update has fixed the issue on my sites.
Thanks John, I have contacted support and reiterated and linked back to this thread. Hope this will have a solution soon!
On further testing, it appears I must have not cleared my cache after the WordPress update. It seems the 5.5 update is the real culprit that’s breaking this. I updated just WordPress on a website with ACF v5.8.11 and recreated the issue.