Instructions in 'Translating new messages' not clear ?

[dsgrangs-paul]

Hello,
I m following your guidelines (https://github.com/nicksnyder/go-i18n#translating-new-messages) but does not seem to work for me, or maybe instructions are not clear and I did understand ?

I have a first set of messages into "active.en.toml" file
I have a 'translated.fr.toml' file which resulted from "goi18n merge active.en.toml translate.fr.toml"
I translated a first set of messages, starting from "translate.fr.toml" and producing "active.fr.toml" file

Then I change my code, bring some new messages, and modify some of them.
Then I want to update the translated version ...

$ goi18n extract => to update "active.en.toml"
$ goi18n merge active..toml => is supposed to generate updated translate..toml files, but in fact it overrides "translate.fr.toml" with only 2 messages (which were neither new, nor changed), moreover it generates again "translate.fr.toml" from scrath, overriding the one which existed.
I m supposed at that step to translate messages into "translate.fr.toml" but this work was done already for most messages !
So this is not clear to me
Can someone provide some support ?