Hi @runpixelrun
This isn’t so much of a bug, but more of a problematic feature of WP and ACF.
When an image is uploaded, WP will attach it to the post which is being edited. This is outside of ACF.
When you remove the image from the field, ACF is only modifying the postmeta, not the actual image, so the connection to the post remains.
To remove this connection is potentially harmful to some websites which rely on the default WP behavior.
For now, your best bet is to hook into the acf/update_value, or even the acf/save_post actions and modify the image connection manually.
Good luck
Thanks
E
