azure-functions-host: Queue Trigger Invocation added to poison queue with no errors, warnings or exceptions

I have a queue triggered function which is occasionally stopping with no indication why. Logs are streaming from the job fine, until it is added to the poison queue.

For example, at 9:41 this job was added to the poison queue

The end to end transaction does not contain any information on why it stopped (times here are in my local time)

But checking the invocation logs from the Function Monitor, it doesn’t even appear there (ignore the other failures, they are from a known issue). See how the OperationId of this function is not listed anywhere:

Investigative information

Please provide the following:

• Timestamp: 11/11/2020, 09:31:10:503 UTC time
• Function App version: 3
• Function App name:
• Function name(s) (as appropriate):
• Invocation ID: 74c8f217-7a4c-434d-8acb-cc6f6a6ebeb5
• Region: Australia East

Repro steps

Provide the steps required to reproduce the problem:

No reproduce, usually re-running the job will succeed. Cause or what the error is is unknown.

Expected behavior

Provide a description of the expected behavior.

The job should succeed, or at least provide information on why it failed.

Actual behavior

Provide a description of the actual behavior observed.

The jobs intermittently fail without an error.

Known workarounds

retry the job

Related information

Provide any related information Function is running on a Premium plan, deployed from Visual Studio. The job is configured to run one invocation per instance at a time.

Here is the host.json:

{
  "version": "2.0",
  "aggregator": {
    "batchSize": 1000,
    "flushTimeout": "00:00:30"
  },
  "extensions": {
    "queues": {
      "batchSize": 1,
      "maxDequeueCount": 1,
      "newBatchThreshold": 0
    }
  },
  "functionTimeout": "00:59:59",
  "logging": {
    "logLevel": {
      "Microsoft.EntityFrameworkCore": "Warning",
      "Function.MyFunction": "Information",
      "Host.Results": "Information",
      "default": "Information"
    },
    "applicationInsights": {
      "samplingSettings": {
        "isEnabled": false
      }
    },
    "console": {
      "isEnabled": "true"
    }
  }
}