Hello Dmitry,
What do you mean by? taped log does not show any failures.
Could you search in the tapeserver logs for the In ArchiveMount::reportJobsBatchTransferred(): got an exception error message? This log line should contain additional information about the reason of the failure. You can see what should be logged for that log line at: scheduler/ArchiveMount.cpp · main · cta / CTA · GitLab
This exception happens when trying to queue for reporting the files that have successfully been written to tape, and as you state in your second comment, if there is a problem with a file, the entire batch will fail.
In the past we have experienced this issue with dual copy storage classes, but it was related to ObjectStore locking timeout. Looks you are getting a different error based on due to presense of already archived files in archive batch.