The issue has been fully resolved.
The issue started when heavy image upscaling API requests overloaded the upload API, causing some API requests to return 504 errors. This was solved but a knock-on effect caused approximately 5% of API requests to fail with a 502 response.
To prevent this issue from happening again, improvements have been made to reduce the load of image upscaling and better distribute load. Changes are also being made to logging and alerting, for faster identification of ...