In the past we were attempting to do a clean installation of higher Drupal version, add to that new instance the Node Import module, and to extract from the old D6 instance the content into the clean D10 instance. Unfortunately Taxonomy numbers always ended up getting scrambled.... so a few sites are still stuck on D6.
I see Node Import has been deprecated, and suggestion to use Feeds instead.
I just want to present a workaround for anyone who used the module field_sql_norevisions or emptied their revision tables otherwise and always finds themself with an empty body or field in the upgraded instance after migration.
The FieldabledEntity prefers the revision data during the migration. But no revision data, no field data.