Wombat Dialer Call stuck in Waiting

[ckanai]

I was trying to get Wombat dialer to place call through queue. Had following setting for end-point.

EP Type: Queue
Description: Wombat
Max Channels: 10
Located at [extension]: 9999
Queue name: 9999
Reverse dialing: checked.

Now this call is stuck in waiting (seen in Queue Metrics Call List) and won't even come through to extensions.

Looked at Asterisk log and also used CLI, but could not locate the channel it belongs to, to terminate it.

Any subsequent attempt to run the campaign results in RS_NUMBER error.

Is there way to terminate this call without restarting freePBX?

[ckanai]

When I checked this morning, stuck calls have disappeared. And after removing Reverse Dialing and  setting Description to 9999.
Tested campaign and it went through fine.

Still would like to know what happened though.