I'm not sure whether this belongs in RStudio or R Markdown, but I think it belongs here. First, the obligatory information: I'm running RStudio 1.1.423 on both macOS (10.13.4) and Windows 10 (17133.1), and R 3.4.4.
When knitting an R Markdown file (I use slidify) to HTML on macOS, the HTML file shows up in the Viewer tab as it's supposed to, complete with Google webfonts.
However, when I knit the same file to HTML on Windows 10, RStudio opens a new window with the HTML file (unlike on macOS, the file doesn't show up in the Viewer), and the fonts are all wrong. To get what the actual HTML file looks like, I have to click on Open in Browser in the new window.
Has anyone encountered this issue, and know why this is the case? Or is this a difference between Windows and macOS versions of RStudio?