Embeded KB page view fails display on JSM portal

[bhanu_kumarin_ext]

Hi team, 

We are on DC Jira Service Desk, and we have observed that the embedded display of KB pages fails with 'refused to connect error.'

However, when the same page is opened in new window, its accessible. The only recent change is that we upgraded Confluence to 8.5.7 and switched from Server license to Dc evaluation license.

Any inputs will be greatly appreciated.