Remote control doesn't work.

In SDP OnDemand, if I open a successfully scanned asset, set the option to "do not prompt user" and click the remote control button, some machines never allow a connection. It just sits on that page for hours. Some work but take an unacceptably long time (a minute or more). Some do work fairly quickly. But if I go to assist.zoho.com I can start a session almost instantly with whatever machine I add to the list by running ZA_access.exe on the target machine.

Now, I know that these two products are integrated so why is it that it works perfectly through assist.zoho.com, but not on sdpondemand.manageengine.com?

Support with ManageEngine is absolutely terrible. They take days to respond, they start a remote session and do not resolve the issue while I'm on, then take days more to get back to me. I want to know if other users are having this same problem.