Images not appearing on site

Has anyone had this issue before and could advise me on the best way to fix it, please?
I have been talking to support for two months now on and off and haven’t really got a solution. PAM seems to be picking and choosing what images will and will not appear on the site. All these images are processed in the exact same way & I have tried to fix it to the best of my ability with no luck.
Every time I sync there is a list of products which images are not being found, screengrab attached below of what appears on sync & what appears online.
Any help would be greatly appreciated as we are only a small business and it more and more stock not appearing online.

Hi @lizmckenna89,

I am sorry to hear that you are experiencing difficulties with your images, and that support has been unable to resolve the problem.

I am flagging this with @ciara.larkin, our Operations Manager, for review.

Thank you for your patience.

Kind regards,