I just finished setting the whole site to use https.
The padlock shows up on Microsoft Edge but it doesnt on Chrome. Actually is does work on Chrome as well but only on pages and not on post.
The issue is that you are loading insecure content from a secure page. This issue is normally known as mixed security warning.
In the past, Chrome was used to display a crossed padlock. More recently, Chrome changed to simply skip the security padlock in case of mixed security errors. This is a little bit less evident for developers.
You can see the issues in the Chrome developer tools, either in the console tab or in the newer Chrome security tab.
but seriously that chrome doesnt post a mixed content warning is annoying.
FF does mark the lock with a yellow warning triangle which shows passive mixed content (gray warning triangle for blocked mixed active content while a slashed lock for enabled active mixed content)