This has been resolved with ACF Version 5.8.1. Thank you!
That was easy: deselecting the “Enable AJAX Search Functionality” worked.
Thanks a lot!
That’s quick. Great! Thank you!
Since two days I had the same problem. Found out that there was a conflict with a plugin called Column-Matic. After I disabled that, the slideshows worked again. Replaced Column-Matic with WP Easy Columns. No conflict.