No activity in the Lambda monitoring console while creating picture conversions

Environment : 10.2 date-based instance with S3, DAM and Lambda Picture Conversion addon

When I create a picture, the picture conversion are correctly executed (I can download the different rendition, and the picture is correctly previewed), but there is no sign of activity on the Lambda monitoring console : no data in the invocation graph for example.

In nuxeo.conf:

nuxeo.lambda.image.conversion=test_nuxeoPictureConversion
org.nuxeo.connect.url=https://nos-test-connect.nos.nuxeo.com/nuxeo/site/
nuxeo.templates=mongodb,s3binaries,lambda