Hi @ivan
Unfortunately you’re experiencing this because you have so many flexible/repeater fields which probably also contain a lot of fields. This is more of a server-issue or possibly architectural issue.
Are you using the ACF-JSON feature? That should help speed things up since you wont need to do so many DB calls.
Other than that you’ll either have to up the specs on your server or rethink the way you’re using flexible/repeater fields. I see many people use a repeater with a google map field for example and complain when it’s loading slow and they have 30-40+ maps rendering on one page (madness). I always tell them to stop using repeaters and use a CPT instead. Problem solved. 🙂
