Error, no connection to the defined proxy server

[Peter_Youssef]

This issue is currently faced in a Managed deployment scenario.

What workarounds should be performed to get it resolved?

My solution:
I've updated the custom.properties file on the synthetic server and it worked for one of the browser monitors and still facing the same errors for another 2 browser monitors.

[ChadTurner]

Are you trying to use a Private Location for your AG testing an internal app? check with networking to ensure communication is allowed.