Non-retryable error executing action: 'gmail/get' cloud.solutions.Common.NonRetryableException
A task was canceled.
This is a temporary item-based error which occurs when exporting items from Google. It's literally a "Non Retryable Exception". It can occur during the migration of any Google Workspace services such as Gmail or Calendar, but the same solution applies to both.
Remigrate the user. This should reduce the occurrence of the error or resolve it completely.