Encountering Timedout communicating with oracle database {0} while stepping thorugh

I was testing a specific behaviour :

I am using No_Trx adapter and the adapter is invoking a Stored proc. The stored proc has explicit sleep of 10 seconds inside it and my Adapter service has a timeout of 3 seconds.

I am encountering Timedout communicating with oracle database {0} while stepping through the code in Developer - which is expected but if I run the program through the developer , its executing successfully. I am not seeing the Timeout exception .

Any thoughts / suggesstions - why the Timeout is not occuring when I run the program .?