Hi,
I tried to replicate the above issue, and noticed the following things
after Publishing the app, the updated description takes around 1 minute or so to reflect in the published app.
also points to note, if you have the older version of the app open in the browser and are trying to check description immediately after publishing, then it won't show up.
please relaunch the app and freshly and please check if you get the notification that new app is available with refresh button.
this will make sure that the description is eventually visible to you in the app.
Kindly please follow these steps and confirm if it has worked for you, else we may have to see what is causing you to get this issue and we are not able to replicate this.