Stuck Queue Issue Resolved
I just wanted to post a possible solution to a stuck queue. If your server or VPS has enough power, just increase the number of queue workers. The extra queue workers will process items that are not stuck, eventually whittling down the queue.
Or another scenario is that the queue is not stuck... it just can't keep up with new items being placed in the queue, so there is a growing backlog.
I doubled the number of queue workers and it started to process again. Probably won't work in all scenarios, but it worked in mine.