There is a race condition which causes a recovery to be stuck.

This happens at time when recovery manager is running and there is a try to run a socket SCAN command or a RecoveryDriver api is about to use to start scan.

When the recovery manager is terminated then it can happen that the Listnener asks for scan to be done, then recovery manager is terminated and the Listener then stops waiting forever.
At that time there is already terminated recovery manager and Listener just waits for being notified that scan finished (we talk about SYNC call).