when anchored objects (such as column Text or line numbers) are anchored in a Text using the options "Paragraph border" and "paragraph Shading" the borders and Shades will "randomly" disappear, or new border-lines will appear (when more then one paragraphs are merged, the lines always appear between the different styles, even though they work fine again when the object is de-anchored). Sometimes the appearance doesn't change when an object is anchored, but when the anchored object is edited (for example, when the size of the anchored object is changed).

This is reproducable on my Windows 10, using InDesign 15.1.4.
Steps:
- create a new document
- create a paragraph styles using paragraph borders/ paragraph shading
- create 1 or 2 more styles, based on the previously defined style
- create an object-style using "benutzerdefiert" (individual?) - positioning
- anchor 2 or 3 objects using this object-style in the shaded text/ the text with borders

expected result:
the paragraph border/ paragraph shading does not change, but looks just like I defined it to look

actual result:
- the appearance of the paragraph changes, and that also affects the PDF.

The problem also sometimes appears when an object is anchored in a text using Paragraph border/ shading, when text anywhere else in the same story is edited.