How do I remove thin lines when creating a PDF/X1-a from a drop shadow area created in InDesign without causing a problem with an Illustrator vector logo image on the same page?

My issue is that there are very thin lines surrounding two small images in an AD that I created in InDesign2019 (MacBook Pro-Mojave) that are not in my artwork, but appear when I export to PDF/X1-a. The 2 images have drop shadows, which I believe is causing the problem. This ad needs to go to a commercial printer so I want to make sure it will not print these fine lines.

I did find a solution using PDF preferences - deselecting the "Smooth Line Art" option, but when I do that my vector logo appears very jaggity.

Please help!

Thanks!