@GitHubish I can't fully understand your scenario and there are no instructions for your reproduction (seems like it's just the playground app).
Please provide a reproduction for your case. generally speaking, if you want to control the language of a specific component you can do that by using the static flag, e.g. lang: '{previewLang}|static'.

Sorry @shaharkazaz for not providing enough in my explanation. What I'm trying to do is display a component in a selected language (so the change is dynamic) and this language may therefore be different from the "global" language of my application. The use case is that of a preview of a page that will be printable, this page is made up of a set of components (graphics) and must therefore be displayed in the language selected in a drop-down list without changing the language of the rest of the application. I use an @input to pass them the selected language and I wanted the translations to change using one of the methods on the "Multiple Languages Simultaneously" page, but this doesn't work. I can't use the static argument as it's dynamic.

I hope this has made things clearer?

new example : https://codesandbox.io/p/sandbox/ngneat-transloco-forked-564v38?file=/src/app/multi-langs/multi-langs.component.html:1,1

Thank you

@GitHubish Thanks, it's clear.
I'll think about how I want to approach this, but generally speaking, the directive isn't listening to input changes and that's the issue here

@shaharkazaz Thank you very much! Also with the pipe, I guess it's the same thing, it doesn't listen to the change and therefore doesn't update the key translation