Some call queues might not be visible when you visit Admin > Call Flows. This is because you may have created a Child queue. A child queue is a queue that is created inside a Parent queue.
Parent Queue: A queue can be considered a parent queue when the queue is created under Admin > Call Flows > New Call Queue.
Child Queue: A queue created inside the parent queue while configuring a call queue and is accessible only inside the parent queue. Usually, a child queue is created when you select "send to another call queue" as the fallback action and click on New call queue instead of selecting an existing call queue.
A child queue will not be visible in the Call Flows tab as it may confuse the user when using the parent queue to route calls to a particular number.