Having a similar issue. Trying to leverage Page Delivery functionality to deliver the experience to multiple pages but the experience only appears on the landing page.
Turns out the problem for me was that all the code I had added in the custom code section was set to save in the head. When I unchecked that box, the test seems to be carried over across all the pages. I hope this helps.
Hi Harshit, Have you tried running the mbox trace to verify that you are indeed qualifying for the activity on the other pages? If yes, it could be that the html page structure is different on the other pages so target is unable to apply the changes. If you are on at.js you can append url parameter mboxDebug=console and see the console in the developer tools to see if there are selector issues.