Attached images won't show up in admin section

Hi,

I have two custom posts using the plugin.
In one of them everything works fine (with pdf and images attached)

On my second custom type, something strange is happening :
i attach an image with the plugin, it works, the image shows up on front.
But when i hit the “update” button the image is not on the wp attachments list anymore, but it is still showing up on the website.
I tried to deactivate all my plugins to see if there was any conflict but apparently not.
The pdf attached work, it only happens with the images.

Any clues ?
Thanks in advance.

https://wordpress.org/plugins/wp-better-attachments/