custom multifield in page properties

I have a custom multifield in page properties which is saving values as json. I am working on AEM 6.3. I am able to add the values in dialog , and on save, it is getting saved as expected in crx/de and reflects on page properly. But next time when I open the dialog, the values are not getting populated with the latest value authored. The dialog is working fine if it is added as component dialog.This is happening when it is a part of page properties.  However, when I hard reload the page, the dialog gets updated with the new values. Please share you thoughts on this or if anyone has faced such issue.