The pages themselves are delivered over https (TLS), but browsers are rightly marking the pages as insecure because some of the assets referenced by the pages are not requested over https. See image.

I know there are people at FL who understand why that is insecure and a risk both to FL and to FL's users, but just in case: https://www.troyhunt.com/heres-why-your-static-website-needs-https/.
Correcting this would also benefit FL in terms of how Google factors security into search rankings / SEO.
Thank you,
Donnie