In reply to Milan Petrović.

The problem is, is that some breadcrumb paths in themes or plugins, seo plugins etc. have the wrong syntax. Even in JSON-LD you can make mistakes and have the issue. It is just because itemprop=”item” element is either missing, empty or is having the wrong value (“url”) in the breadcrumb url a-tag. That is just all. If you do it right you do not have the issue.