It all depends on how you set up Notifications in your account Settings. You need to turn on Language Progress notifications (Translation or proofreading for a
certain language is complete)
Do note that you will receive a notif only when all the files are translated/proofread for that target language. You will not be notified about every file being complete.
So please check whether your project has languages with 100% progress bar.
Is there no way to get notified when single translations are made?
People rarely complete whole languages, and since I don’t check every day, useful translations get unused for weeks before I notice them.