Safari Web Notification prompts for permission on my developer machine, but doesn't on any other machine

Hi, I have followed the instructions as per the documentation, and I am able to generate a pushPackage successfully.

It seems to be only working on my safari browser, i.e. it asks me for the permission and upon granting the permission I do get a deviceToken.

But when we try to visit the same site on my colleague's safari browser, it gives a permission denied in browser console, while the logs show "Signature verification of push package failed"

Has someone else faced this issue before?