When an execution times out and the worker channel restarts as a result (here), no exception is passed into the call to shut down the existing channel . This results in TryFailExecutions() exiting early, and mid-flight executions are not failed properly as the worker channel shuts down.

If a timer trigger function is mid-execution during a worker channel restart like this, this scenario is particularly bad because the timer trigger won't run again until the previous execution finishes (which in this case won't happen). This can be mitigated by restarting the app itself.