Important: For images that are more than 50% of the max size, make sure that you use the parameter scale=false. Otherwise the upscaling pushes the image dimensions beyond the image size limit. The scale=true parameter improves the OCR results for small and low DPI images only.
If you still get the issue with scale=false, please provide this image for testing and we will check this ASAP.
See also Difference between online OCR and OCR API? - #2 by admin