It has been found that Webdriver monitor can be executed successfully for on-prem stations but not for the global stations.
DE644623 - Integration with the browser agent was found enabled.
Disable the integration with the browser for problematic monitor as shown below as it is slowing down monitor jobs and in some cases, depending on logic under monitor can lead to certain errors "Script failed at step 1: Assertion failed after 30 seconds" preventing successful execution.