Thank you for using our services.
There are two possible configurations, which, if not set, might cause this behavior, Please verify that you have set a Page where this content is published page in your feed (screenshot1). Also, make sure that the blog, which contains the problematic blog posts, has a Default page set in the Title and properties for the blog. (screenshot2).
Let me knoew if you need additional assistance!
the Telerik team
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