I read stories using Feed View in Full mode.
I have the Style menu set to Palatino / Georgia, which has worked for a long time now.
Suddenly in the last hour, the fonts seemed to change. I noticed in the console that NewsBlur tries to load https://cloud.typography.com/6565292/711824/css/fonts.css, but it fails with a 403 Forbidden error. At the moment, an inline style is forcing fonts to be
font-family: "Lato", "Trebuchet MS", sans-serif;, instead of my chosen font.
I am using Firefox 66 on macOS 10.14.2.