Bug- First Corinthians: An Exegetical-Pastoral Commentary

This appears to be intentional. It even shows up in the preview pages on the product description page:

But it's weird. There doesn't appear to be any rhyme or reason for where the highlighting appears, and I agree it was probably in the original digital files that Logos received (I doubt this was made from scanned hard copy, because of how the preview shows up; usually resources that come from scanned hard copies show up just as scanned images).

Todd Phillips said:

Rosie Perera said:

But it's weird. There doesn't appear to be any rhyme or reason for where the highlighting appears,

It looks like the Application sections have the grey highlight.

I think you're right. The whole commentary is available free in PDF format here: http://openoureyeslord.com/2012/05/21/free-commentary-on-1-corinthians-2/. And the highlighting is preserved in Logos exactly as it was in the original.

Since this is a Logos edition book and not a Vyrso one, they should have gone the extra mile and implemented those Application sections as shaded grey boxes rather than highlighting. They have the ability to do that and have done so in other resources such as the Word in Life Study Bible (excerpt below). It looks chintzy with just the highlighting, and could get in the way of user highlighting.