Vimeo not playing because link is HTTP not HTTPS

I need some guidance. Some years ago our fired-for-horrible-work web dev contractor build a child Enfold theme for us, using the exceedingly bad practice of copying and editing entirely too much of the parent theme, so whole chunks of code never get updated. Now that we’ve switched the site from HTTP to HTTPS, Vimeo videos aren’t playing because the URL isn’t getting constructed with HTTPS. I need guidance on where to look to fix this.
I found a reference to frogaloop in the support forum, I replaced that function in avia.js (which has been heavily modified) with the latest version, that didn’t fix it. Where else can I look?