Some users cannot type "@" sign into InputField (international keyboard layout issue)

My Unity app uses e-mail login, but some international users aren't able to directly type the @ symbol into the InputField in my app. It seems related to the keyboard layout that they are using. They are, however, able to type the symbol elsewhere outside my app.

Is there a workaround that I, as the developer, can implement?

It's a pretty big showstopper when many users can't register and log in to start to use my app (my app has a very international user base). I need to collect e-mails...

Some users cannot type "@" sign into InputField (international keyboard layout issue)