Some call queues may 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 created under Admin > Call Workflows > 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 Workflows tab as it may confuse the user when using the parent queue to route calls to a particular number.