Why does my pop-up configuration disappear?

[MaheshPatel1]

Hi, could you please explain why my configured pop-up shows the new configuration correctly in a web map but not in a web app (such as a story map). If I save the web map after adding my HTML code I can still see the desired configuration, whereas if I close and re-open the web map the same problem arises--that is, the pop-up shows the actual HTML code and not the configuration. This is extremely frustrating as there are no error messages as such. 

This is how the pop-up looks when I save the web map.

This is how it looks in the web app:

The attached text document shows the HTML code I used and one of the expressions that was referenced in the HTML code.

Any help with this would be much appreciated,

Mahesh