"Copy URL to Clipboard" keeps on loading on Case Table

When we use the "Copy URL to Clipboard" Context menu button on the Case table List view, and try to access the link on a new tab, the Case keeps on loading for 15 - 20 minutes, However the same case can be opened by clicking on the List view "case link".

We have looked at the context menu button scripts, the context menu button is in Global scope therefore can not make any changes to the link to fix the issue, Creating new context menu button on the customer Service Scope has been ruled out.

What could be the reason for this behavior and how can we solve this issue, Permanently?

Attaching screenshot of the button, Button script [in Global Scope] , and Sharing Sample URL.
SAMPLE URL :: https://InstanceName.service-now.com/nav_to.do?uri=sn_customerservice_case.do?sys_id=5SDFB554f6A65G4...