Uncaught DOM Exception of Cross origin request renders page unauthorable

Has anyone encountered this in the past couple of days? All of a sudden in some pages in author instance, we are unable to edit anything since the OOTB scripts required for authoring are blocked due to a new Uncaught DOM exception caused by a cross origin script request. 

The funny thing is, the same error does not occur if I rename/move the page somewhere else. Everything works fine via IP and the issue occurs only while accessing via DNS (all authors access via DNS). I've checked the CORS OSGi config and we don't have any and we have never had any. 

This is the actual error,

The exceptions are also not valid since there are no cross origin resource request since the actual request to these scripts are made by the same DNS. We have not done any changes or deployments to both AEM or dispatcher in the past weeks and this started happening only since the last couple of days.