Only seeing this issue on certain pages.

Same here

This is the expanded details

Any feedback to offer?

This means that although the page was loaded securely, there was something on the page that was loaded insecurely. This is almost always content not actually hosted by TexAgs, but some other third party. It can be an image posted by a user, or content loaded through an advertisement.

Your connection to TexAgs is still 100% secure, but if you would like to remove those insecure third party requests (and not just on TexAgs, but other sites as well), and you are on Chrome, I would recommend this extension, which has an option called "Encrypt All Sites Eligible" that will change most insecure requests to secure requests.