Hello Clotilde,
Thanks for the attachments.
Can you please check if transaltions for 'tab' are not exported as part of the schema?
I mean if you export the schema from the source system and import it to the target, just check if the translations are present on the target system?
If not, you can try one simple work araound. Just add the missing translations to some dummy form in the pacakge (as disaply name or something else), they will be exported with the package. And importing them on the target will add them in the db.
Regards,
Stefan