Well, FileMaker uses a webviewer internally and the browser plugin is loaded to show PDFs.
And Adobe can limit that.
On a mac you can remove that by removing the Adobe plugin and using Apple's plugin.
Or you use MBS Plugin to make preview pictures from PDF and show them.
Is this in a list view? If so, change it so the container is only in a form view. At least that's recommended for interactive containers.
Thanks, the layout displays in form view only.