Mystery line added to PNGs exported out of INDD

I have a document that has a single TIFF/PSD per page, 35 in total. Each image has been scaled to the others in InDesign, which is why I can't just save out of the original linked files in Photoshop. Each page/image needs to be exported as a PNG with a transparent background. The products have a drop shadow created in the original file. When I export them out of InDesign as jpgs, this issue doesn't arise. But as PNGs, most of the images are exporting with a black line in the drop shadow. Not the same length or width, that changes image to image. I tried several attempts and even which file gets this mystery line seems to randomize.
I checked the usual suspects, looking at the frame and the contents, accidental strokes, I also removed all guides and margins. I tried on a different computer as well. Same crappy result.
Using InDesign 18.0 on an iMac (24-inch, M1, 2021) running Monterey 12.6.