Thanks for sharing your issue here. The Developers Console showing
Failed to load is unfortunately not very indicative of what the underlying issue actually is. I've reached out to you privately as I would like you to provide a
HAR capture to include the network responses you receive in the Developers Console when seeing the
Failed to load message. This network response may give a better idea of what the issue is.
For the time being, if you're trying to completely wipe the queue, have you tried removing its definition from queue.yaml entirely, deploying and then redefining?