fix issue #200

Author: chqy24

src/shared/components/challenge-detail/Header/index.jsx

@@ -66,7 +66,7 @@ export default function ChallengeHeader(props) {
 
   const theme = themeFactory(trackLower);
 
-  const stylizedSubTrack = (subTrack || '').replace('_', ' ')
+  const stylizedSubTrack = (subTrack || '').replace(/_/g, ' ')
     .replace(/\w\S*/g, txt => _.capitalize(txt));
   const subTrackStyle = `${trackLower}-accent-background`;
   const eventStyle = `${trackLower}-accent-color`;