I am having a similar issue. I created custom templates but they didn’t work for me either. What theme are you using. I am using the Cutline 3 column theme.
I can access them and edit them in the “theme editor” section of the admin panel, but when I try to visit the section online, it isn’t there.
Stranger still, some of the default templates, like the “Sitemap” don’t work either, but the “Archives” page does work.
I would love to help you on this, but I haven’t received any help myself.