Change and translate the label "Frontend Language" in the registration form.

Hi,
May I know how to solve the problem with redirecting the user to his profile in the selected language as Frontend Language?
The cb-login module is translated with Joomfish to redirect the user after login to the profile in the corresponding languages ​​(see image).
The users choose the language from the "Frontend language" (required) and this is saved in their profile.
But the user who has chosen, for example, the French language, when he makes the login, if the login page has the url in English, he is not redirected to the profile in French, but always in the language active in the url at login time, ie in English.
May I know how to solve?
Thanks

It's a bug with the language userparams not taking affect. If you want to redirect to a custom substitution supported URL you can do that with CB Auto Actions and its Redirect action on the after login trigger. Your redirect URLs need to also be non-SEF. Example as follows using CB Auto Actions.

index.php?option=com_comprofiler&lang=fr

To get their language you'd use the below substitution, but I doubt it's going to work as it uses the same API as login normally would which appears bugged.

[cb:config param="lang_tag" /]

The problem with the above is it gives results like "en-GB" instead of just "en".

So with all that said I don't have a workaround for you, sorry. I have yet to investigate the bug and fix for next CB release.