I’m having the same issue as this thread: https://kriesi.at/support/topic/mixed-content-on-my-homepage/
Theme is up to date
SSL insecure content fixer installed and activated
failing on the images within wp-content/themes/enfold/config-woocommerce/images/
Re-installed theme from scratch and it seems to be working now.
I was one of the users having the issue with the updater saying “Download failed. Forbidden” as well, so perhaps the two are connected?