Job failed to run and StateName = NULL

Hi

We have a hangfire instance running in a non-scaling always-on Azure WebApp. We had a task that failed to execute so I tracked it down to a chain of 7 tasks making use of BackgroundJob.ContinueWith. The first 3 tasks were created and executed correctly, the 4th one was created with StateName = NULL but didnt run and the last 3 werent created at all.

Raw Data:

UI:

We have executed these chains of tasks 1000’s of times without fail so are unsure how to investigate this issue. Any ideas how/why this is happening?