Did some more debugging today and found a couple of issues.
When placed as a ...

Did some more debugging today and found a couple of issues.

1. When placed as a block, the required JS were not loading. I had to explicitly load them using hook_page_attachments_alter()
2. Looks like the library is not able to properly hook into the HTML and therefore the widget is not appearing

Second point elaborated:

This is the HTML where the widget is not appearing - as block.

This is the HTML where the widget is appearing - as page.

Not sure what is causing the problem. Any help is greatly appreciated.