Scheduled workflows not started: "{error: Workflow task not found.}"

Good morning,

We’re getting unexpected errors when trying to run scheduled workflows. The error comes from the matching-engine component and says: “Workflow task not found”.

The workflows are scheduled every 5 minutes. Up to 2000 workflows they all start and complete. After increasing the number of scheduled workflows we noticed that several runs never started. When we scheduled 6000 workflows less that 2000 were starting every 5 minutes and the error we got was the above.

Looking around I couldn’t find any relevant topic so I would appreciate your feedback.