It has nothing to do with the files existing.
ACF stores and attachment ID (post ID) in the database for the image field. It gets and returns the image that is associated with that ID. The code that you provided indicates that instead of the correct image that the site is showing some default image ...no-profile-picture_3.png.... This means that the image ID stored by ACF, if there is an image ID stored by ACF is incorrect. This can be checked by going to the page/post/user where this image is set and seeing if the correct image is shown.
I am just guessing that the ID is wrong based on what you have provided.
