Drop shadow in exported PDF is a different size
Certain drop shadows have a different size when they appear in an exported PDF.
In the attached example, the black shapes each have a drop shadow effect in yellow. When exported, the shadows appear shorter and narrower. The difference is approximately 20 pt narrower and 1 pt shorter. (Note the difference in proportion of the yellow drop shadow and black shape in the screenshots.) I've also included the drop shadow effect attributes.
This occurs with multiple PDF export settings including the default [High Quality Print]. I am able to reproduce this behavior in both InDesign versions 15.1.2 and 16.0.
Thanks for reporting. We will review the issue shortly.
CS5 omachi commented
This is a symptom that only occurs when a negative value is entered for the drop shadow size. The display in InDesign is strange, and the PDF is correct (according to the settings)