@ Leland
re: Connections interface does not allow for a choice of http or https. In fact, it doesn’t allow choosing an image from the Media Library. It only allows an upload from your computer. I tested this yesterday by adding a new image with the same results.
This is absolutely correct for only the logo and image upload fields. There is no need for you as the user to choose http or https, Connections will take care of that for you when displaying those two images. You can verify this. All the logos are infact being served using https.
The issue… the images in the notes fields that are giving you the mixed content warnings, those were manually entered into the text area of the notes field by either copy pasting the URL of the image or using the Add Media button and inserting the image from the Media Library. In either case, my previous reply is still the solution. You need to edit the URL of the image in the notes field to be https.
