For number OCR usually OCREngine2 is better. Also, often it helps to select Chinese(!) as the OCR language. Then the OCR logic detects single digit numbers better:
@ocr-api-team used the free online ocr website to test the image. This website and its ocr api are also from us - so the website uses exactly the same ocr engine as Ui.Vision In other words, the online ocr website is a convenient way to test various OCR settings and then use them in the RPA software.
The below macro shows how to do this OCR in the RPA software. You can set the !ocrengine and !ocrlanguage variables.