Please see attached tape.cfg, tap-job.cfg and task log.
tape.cfg
changer: MSL2024
export-slots 1,22,23,24
path /dev/tape/by-id/scsi-DEC83807ZS
tape-job.cfg:
backup: Weekly
comment Backup storage01 to tape every week
drive drive0
export-media-set true
pool Pool1
schedule sat 12:15
store storage01
tape-log:
2021-10-09T12:15:00+02:00: waiting for drive lock...
2021-10-09T12:15:00+02:00: Starting tape backup job 'storage01

ool1:drive0:Weekly'
2021-10-09T12:15:00+02:00: task triggered by schedule 'sat 12:15'
2021-10-09T12:15:00+02:00: update media online status
2021-10-09T12:15:00+02:00: starting new media set - reason: policy is AlwaysCreate
2021-10-09T12:15:00+02:00: media set uuid: 0121f847-86a9-40c1-bc63-651d27e7b5e2
2021-10-09T12:15:00+02:00: found 64 groups
2021-10-09T12:15:00+02:00: backup snapshot ct/100/2021-09-24T20:00:02Z
2021-10-09T12:15:00+02:00: allocated new writable media 'BAZE04L7'
2021-10-09T12:15:00+02:00: loading media 'BAZE04L7' into drive 'drive0'
2021-10-09T12:15:50+02:00: found media label BAZE04L7 (e31f49f9-1f06-4f84-8aea-6bff1a295162)
2021-10-09T12:15:50+02:00: writing new media set label (overwrite '00000000-0000-0000-0000-000000000000/0')
2021-10-09T12:15:55+02:00: moving to end of media
...
2021-10-10T17:57:14+02:00: percentage done: 100.00% (64/64 groups)
2021-10-10T17:57:14+02:00: append media catalog
2021-10-10T17:57:14+02:00: eject media
2021-10-10T17:58:48+02:00: unload media
2021-10-10T17:59:57+02:00: exported media 'BAZE04L7' to import/export slot 1
2021-10-10T17:59:57+02:00: TASK OK
pmtx status
using device /dev/tape/by-id/scsi-DEC83807ZS
Transport Element (Griper) 0: Empty
Data Transfer Element (Drive) 0: Empty, Serial: CZ2839091B
Storage Element 1: VolumeTag("BAZE04L7")
Storage Element 2: Empty
Storage Element 3: Empty
Storage Element 4: Empty
Storage Element 5: VolumeTag("BAZE05L7")
Storage Element 6: VolumeTag("BAZE06L7")
Storage Element 7: VolumeTag("BAZE07L7")
Tape with volumetag BAZE04L7 is actually located in Storage Element 4 at this point, which is after backup has completed.