@lebarhon sometimes the “default” labels change because the code has changed, other times they change because they were incorrect. Whenever I edit an existing label I try to remember to delete it from all other translations, but I don’t always do that (sometimes I forget, sometimes it’s not possible, sometimes someone else does the changing), as is the case here.
To get the Francais translation up to date and correct, you should find all keys related to noise reduction (not only new keys, but already-translated ones as well!), check what they are in “default”, and translate from “default” into Francais.
Does that make sense?