Swamy, vaikuntam is not subject to any changes but it is said bhagavan gave a small part of vaikuntam to brahma and brahma then gave it to his son manu who placed it on the southern shore of sarayu river- which is Ayodhya !!.
Then a small portion of vaikuntam had gone away and external change has occurred. Isn’t it?
Kindly explain swamy
Adiyen