It appears to be due to some rules trying to undo certain highlighting on Javascript. It’s different because the top is marked as hljs javascript versus the second which is lang-javascript hljs.
.hljs-keyword,
.javascript .hljs-title,
.nginx .hljs-title,
.hljs-subst,
.hljs-request,
.hljs-status {
color: #333;
font-weight: bold;
}
.javascript .hljs-title,
.lisp .hljs-title,
.clojure .hljs-title,
.hljs-subst {
font-weight: normal;
}