I’m having this issue since the first beta of v5.
I just updated to version 5.7.2 and still have the issue.
The strange thing is that not everybody working on the site(s) experiences it.
The otehr strange thing is that the page updates can be saved by clicking in the title field and hitting enter. It’s specifically the Publish button that doesn’t work => AJAX stuff.
Finally – this issue not only affects pages, but menus as well. It’s totally impossible to save any menu change if ACF 5 is active.
