Each proxy comes with two types of time limits: session and idle timeout.
Session Timeout is the maximum time (in seconds) a single proxy connection can run without interruptions. When that time is reached, the proxy connection automatically terminates. No worries, though, because the connection will initiate again automatically.
Idle Timeout is the maximum amount of inactivity (no data sent) before a proxy connection is terminated.
You can easily do that if you need to adjust your session and idle timeout settings on the proxy settings page.