Having the same issue. Removed some testers and not getting 422 error. I can't even test builds of my own app on my own hardware anymore.

Some came through - some failed, which is better than 'Processing' - but it looks like things are back to normal. May have been a backend issue.

Same issue. Started yesterday for me. Had one out of 4 builds work. They're all the same, so not sure why one worked but the other 3 did not. Been Over 24hrs and they are still in Processing.