Why does my https:// page gets redirected automatically to http://

I have an SSL installed on the server. If I try to access a page using https:// it automatically gets redirected to http:// Why does wordpress do that?

If I try a non wordpress page, it works just fine.

Site: Galuppisotg.com
Page trying to access securely (gets redirected): https://galuppisotg.com/menu/
Page outside of wordpress that works securely: https://galuppisotg.com/test.htm