Connect to ATP database using Cloud Shell - IO Error: The Network Adapter could not establish the connection

Connect to ATP database using Cloud Shell - IO Error: The Network Adapter could not establish the connection

Today, I was trying to connect to my ATP instance through the Cloud Shell and encountered with error,

Error Message = IO Error: The Network Adapter could not establish the connection (CONNECTION_ID=uHg0tQ3uSESoYdqEoM9U2Q==)

At first, it seems to be a connection issue or TNS issue. But do you know what the real problem is?
First see, How am I connecting to the ATP in Cloud Shell.

It will prompt you on this screen.

Now, I ran sql /nolog to connect to the sql prompt. And then set the cloud config with ATP wallet.zip file

SQL> set cloudconfig WalletXXXX.zip

and then tried to connect to admin user by using following command

SQL> connect admin/<youradminpwd>@XXXXprod1_tp
  USER          = admin
  URL           = jdbc:oracle:thin:@z!q%xdU@XXXXprod1_tp
  Error Message = IO Error: The Network Adapter could not establish the connection (CONNECTION_ID=EfqZQt86R6a9NCZ6ELHjRQ==)

See, what I encountered the error. "IO Error: The Network Adapter could not establish the connection"

Don't you foresee it's connection issue or TNS issue? I assume the same. But this is not a connection issue.

Now if I connect admin using the following method, it runs successfully.
SQL> connect admin@XXXXprod1_tp
Password? (**********?) ************
Connected.

Please find below screenshot as well for your reference.

This is looking weird but this is the fact.

Happy Cloud Shell

Thanks & Regards,

Chandan Tanwani