Hi Bryan,
You have got a point feature layer added in your web map. But the web map used in the sample has a csv or shape file added to the web map.
Refer to short list tutorial Shortlist Tutorial | Story Maps | Story Maps step 4, i suspect you have not done that for your web map.
I managed to get the map visible by adding if else block around line 639 to 660 in app\main.js. Digging the code further, it's looking for a layer added through step 4 in the tutorial.