In ArcGIS Pro 2.3.0 there is a faint "border" around images (in the PDF export) for images I've placed in their own data frame in layout view (see below). I wish for these images to not have borders and blend into the white background as it appears within ArcGIS Pro. These images have white or transparent backgrounds and I have ensured that the image/dataframe has no borders, drop shadows, etc. I have recently switched to ArcGIS Pro from ArcMap 10.5.1, where I never had this issue using the same images in layout view.
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