Sharing samples, galleries, and sending Layout PDFs are using Amazon cloud service (AWS) with eu-west-3 in older neoCatalog installations (version unknown). The service has different regions. Using eu-west-3 has a limit on the Amazon service region that can cause a sending problem and sent items won't arrive. This is visible in the log:
|The bucket is in this region: eu-west-1. Please use this region to retry the request (Service: Amazon S3)|
Without neoCatalog advanced preference "aws_region" we use eu-west-3 by default, but we should use region eu-west-1. Change the preference, save restart after the preference has been changed.