lightning-file-upload in LWR site

Hi, 

I'm experiencing a issue with <lightning-file-upload> in LWR site when the component is deployed as part of a Second-generation managed package. The same code works perfectly fine with unpackaged code in a scratch org. what could be the issue?

The Issue: 

When I click the "Upload Files" button, I see this JavaScript error in the browser console: 

[ERROR] Failed to load modal. Please contact your Admin. TypeError: i.open is not a function 

UPDATE: I have observed that it is working in Site Preview but doesn't work on published site