Few points which would be of help to you :
1) What is the Windows version & Informatica Agent version you are working on? There are some unresolved issues with using the Cloud Secure Agent with Windows 10 before a few months back. Not sure if it is resolved now? You may check the forum on those lines for a solution. You may also try with a earlier version of Secure Agent to check if it is working fine. I had replied to the same question in a different thread a few months back. Not able to get the link to the thread now. You may search in the forum. You should be able to find it.
2) Check for network connectivity issues which you may not be aware of. The Informatica Cloud Secure Agent is mostly blocked by proxies, company network firewalls & other security software as it provides direct ODBC & other connectivity to databases. Check with your Network administrator. I faced a similar issue & solved it with the help of my company network administrator. The issue will be very specific to your scenario. Can't provide a generalized solution here.