When a queue is stopped, then modifying the queue's max slots will make the queue active. All jobs within the stopped queue will begin to run again.
Queue is initially stopped, and job is in "waiting" status:
Max queue slots are modified to a different number:
Now the queue has started and the jobs in the queue are active:
Release: 12.1, 12.2
Component: AUTOMATION ENGINE
This is a bug that will be fixed in the following versions:
Automation Engine 12.1.2 – Available
Automation Engine 12.2.0 – Available
Workaround: Modify the queue while it is active.