I’ve looked into this and as far as I can see there isn’t any way to make ACF validate that there is content in either post title or the post content when they are included on a front end form.
In order to do this you would need to create an ACF field for the title and/or the content for you front end form make these fields required. Then you’d need to create an acf/save_post filter to update the post title, post content and post slug fields.
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