Delete Media Files When Delete

I changed the field to file_upload and the video and the image is still not attached.

I am using this via the Frontend Submission plugin if that helps.

Here's a sample of my metabox.

   $meta_boxes[] = [
        'title'      => 'Video Information',
        'post_types' => 'ctavideos',
        'id' => 'ctavideos',
        'hidden' => array( 
            array( 'ctavideos_kind_of_player_select', '!=', 'standard' ),
            array( 'ctavideos_kind_of_player_select', '!=', 'ctaplayer' ),
        ),
        'class' => 'fieldwrapper',
        'columns' => 12,
        'fields' => [
            [
                'type' => 'heading',
                'name' => 'Video Details',
                'desc' => 'Select your video and upload it to our system. Your video should be in an mp4 format in order to display correctly. If it is not in an mp4 then you must convert it first.',
            ],
            [
                //'name'  => 'Video Upload',
                'placeholder' => 'Click the "Select" button to upload your video.',
                'id'    => 'ctavideos_video',
                'type'  => 'file_upload',
                'columns' => 11,
            ],
            [
                //'name'  => 'Poster Image',
                'placeholder' => 'Click the "Select" button below to upload an image.',
                'id'    => 'ctavideos_posterimage',
                'type'  => 'file_upload',
                'image_size'       => 'medium',
                'columns' => 11,
            ],
            
        ]
    ];

Update... I went through same tests, this time with the Frontend Submissions Plugins installed rather than using it through. Metabox AIO. The results where still the same.

The only two upload fields that work properly are... file and image uploads. These two the media upload is attached to the post in the Media Library.

The other upload fields that I have listed above.. DO NOT attach to the post and are listed as "Unattached".

I am currently using similar code to this article you posted... https://www.isitwp.com/remove-featured-image-deleting-post/, modified to remove custom post type attachments upon deletion.

The issue is this...

1.) In my custom post type, I am uploading an image and a video along with other information.
2.) When I look in the Media Library the image and the video uploaded is not attached to any post it is shown as "Unattached".
3.) The only time this does not happen is if I change the fields I am using to the "image" field or the "file" field. When using either of these fields the files will show in the Media Library as "Attached".

So even using code such as you suggest in the link above, if I am using fields such as "video", "file_input", "file_advanced" or "file_upload" the code will not work because the if you use any of these fields, the file will upload as "Unattached" in the media library.

Shouldn't using any of these fields result in the media being attached to that specific post?

See my point?

Ok, after a HUGE amount of testing I figured it out exactly what the problem is with the media attachment issue.

I created a metabox with every option of upload. I tested with an image and a video.

My first test results are here...
https://ibb.co/C7BXYCS

As you can see image_input (shown as select by mistake), file_input, file_advanced, image_advanced, single_image, and video are shown as UNATTACHED.

Seeing your results were not the same as mine, I tried to figure out what was different. The difference is, I was using a Custom Post Type and you were either using a metabox on a "post" or "page".

So I changed all metaboxes in my test to display on a "page" and I reran all the tests again.

Here are my second results...
https://ibb.co/Qns93NQ

As you can now see, when the same fields are uploaded via a "page" metabox everything works perfectly as it should and every upload is attached to the post as it should be.

So the problem is image_input, file_input, file_advanced, image_advanced and single_image fields DO NOT attach to the post if you are using a custom post type.

So this is what needs to be fixed.

I hope this makes sense.

Thank you for your responses. I do appreciate them, but we are not quite understanding each other as to what the issue is.

I've made a video showing you the difference in the database.
https://www.youtube.com/watch?v=bjun2ljc4IA