Problem solved. Dan at Medium.com figured out that TypeKit doesn't do well when browsers are configured to not send referrer headers (e.g., in Mozilla, setting

Problem solved. Dan at Medium.com figured out that TypeKit doesn't do well when browsers are configured to not send referrer headers (e.g., in Mozilla, setting network.http.sendrefererheader to '0'). There's a comment thread here on this, but I figured I'd add a top-level comment about it.