If change_default = True, when the field's value changes, Odoo will check and may update the default values in ir.default based on the corresponding conditions.

Conversely, if change_default = False, even if the field meets the conditions in ir.default, changing it will not trigger any updates from ir.default.

In summary, change_default determines whether the field can affect the default values set in ir.default.

Hi,

Please refer to the solved forum:

1. https://www.odoo.com/id_ID/forum/help-1/fields-definitions-parameter-change-default-97660

Hope it helps