Workflow sometimes fails to transition to COMPLETED

[ockernuts]

Describe the bug
We sometimes see a Workflow in which all the tasks are completed, but still, the workflow doesn't transition to 'COMPLETED'.

Details
Conductor version: 3.16.0
Persistence implementation: Postgres 14.1
Queue implementation: Postgres 14.1
Elastic search 7.17.11
Lock: Redis or Zookeeper??? -> see attached server_config file
server_config.txt

To Reproduce
We only see this very spuriously

Expected behavior
The workflow should transition to 'COMPLETED' when its tasks are done.

Screenshots

Additional context
When we pause the workflow and resume it, it completes.
It is the same as this old bug report on Netflix Conductor