title: Celery: Worker with concurrency and reserved tasks only running 1 task
body: <p>Some of the tasks in my code were taking longer and longer to execute.</p>
  
  <p>Upon inspection I noticed that although I have my worker node set to concurrency 6, and 6 processes exist to 'do work', but only 1 task is shown under 'running tasks'. Here is a little visual proof:</p>
  
  <p>Here are the worker options:</p>
  
  <p><img src="https://i.stack.imgur.com/V3iLZ.jpg" alt="The worker options, as seen by flower"></p>
  
  <p>And here is the task tab for that worker with only 1 running process:</p>
  
  <p><img src="https://i.stack.imgur.com/43xa6.jpg" alt="enter image description here"></p>
  
  <p>I have found that if I restart celery, the concurrency is once again respected and i will see >1 running task, but after some amount of time/tasks it reverts back to this behavior.. </p>
  
  <p>Any ideas for fixing this intermittent problem?</p>