We have identified and issue with queued REST API requests returning errors for some customers between Dec 5t0h ~11:00 and Dec 6th ~10:00. It did not affect all the customers, but some may have experienced issues with queued API request returning 'internal server error'.
Incident team resolved the issue in the related incident: https://apsispro.statuspage.io/incidents/1xqtvddgrq02, and have introduced changes and planned additional actions to reduce the risk of this happening again.