Can you follow the steps below do debug the issue:
Use AWS console (https://console.aws.amazon.com/rekognition/home?region=us-east-1#/face-detection) to confirm that you have valid image format and Rekognition is able to detect faces in that image.
As you call the Rekognition APIs what is the response you are getting?
If you are using a Rekognition collection, you can also use Describe-Collection (https://docs.aws.amazon.com/rekognition/latest/dg/API_DescribeCollection.html) to see the face count in your Rekognition collection and confirm that faces are being added to the collection.
Please let us know if there're any other issues using the API.
Rekognition Collection Limitasked a month ago
Rekognitionasked 3 years ago
Unable to create Rekognition project in Console nor cliAccepted Answerasked 2 years ago
Rekognition Label Hierarchyasked 2 years ago
Unable to train model: Amazon Rekognition experienced a service issue.asked 3 years ago
AWS Rekognition ResiliencyAccepted Answerasked 6 months ago
AWS Rekognition: Search Faces in a Collection issueasked 8 months ago
Costs for Batch Rekognition OCRAccepted Answerasked 10 months ago
How to load annotation from local computer in Amazon rekognition custom label serviceasked 3 months ago
Amazon Rekognition: When I create a new Stream Processor with S3Destination definition, this field is ignoredasked 3 months ago