So I ran into this same issue with my site. I think the formidable update changed it so it stopped working. Basically it came down to the stylings of the formidable form I was using on the page was not being saved as HTTPS. Not sure if this will fix your issue, but found that I needed to physically go into the “Formidable -> Styles” through WordPress console and go to the Styling page securely. So have it be HTTPS:/url to the style page for formidable. Once I was able to get to that style page for formidable under SSL I just resaved my form settings for the style and it fixed the issue. Apparently formidable doesn’t save their urls with just the //path, they set it to be http or https themselves. And you have to save the settings one way or the other to change those paths. Once I did that the fonts were fixed and the ajax call was over HTTPS and it all started working again.
With the same issue I found that I couldn’t get to the style page over HTTPS because the HTTPS plugin I was using to make the post/page secure also had a setting forcing non-secure pages to redirect to alway non-secure urls. So I could never load the style page https. WordPress HTTPS was the plugin, so I had to disable that setting before it let me get to the style page HTTPS.
Also I wasn’t able to get to the style page over HTTPS in firefox. I think the settings were cached, so just jumped to IE, it was secure, and saved my settings.
Sorry, not the best explaination, but if anyone finds this with the same issue, that’s how I fixed it. Good Luck. ??
