https://www.logos.com/product/27493/lexham-research-commentaries-pauls-letters-collection
This one specific product page is flagged by Microsoft Edge as not fully secure.
"Your connection to this site isn't fully secure. Attackers may be able to see the images you are looking at on this site and trick you by modifying them."
Hadn't experienced this before. Perhaps one of the images is being loaded from an insecure site? I don't know.