[Plugin: Advanced Custom Fields] It resets automatically and removes the other fields

I’m having the same problem. When I hit update, it redirects me to a new post page and deletes the entire custom field group I just created.

Exactly the same behaviour here. Funny, it was working before (I already have three field groups on the list), now doesn’t work for some reason.

Any ideas, possible fixes?

In my case it’s a conflict with the Post Type Switcher plugin (there’s a bug in it, nothing to do with ACF). There’s a fix posted here (haven’t tried it, will just disable the post type switcher):

https://www.ads-software.com/support/topic/post-type-switcher-bug-with-advanced-custom-fields