Hi,

This was a bug which get added recently and it has been fixed in the core. If you are using on premise installation, you can pull the latest source code or if you are using odoo sh or odoo online, the source code will get updated weekly, so in two days you will receive the updated code.

Mean while, if you need to import the transfers, you have to add a column in the lines, which mapped to reserved quantity in the lines and set its value as 0.

Related Commit:  [FIX] stock: error when importing done qty w/o providing reserved qty

Thanks

Muchas gracias, lo recomendado me funcionó también para la v14.