If you're on a browser, it'll open a compose page with the link's email in mail.google.com and if you're on mobile, it should open in the Gmail app if installed

If you're on a browser, it'll open a compose page with the link's email in mail.google.com and if you're on mobile, it should open in the Gmail app if installed (After 3-ish seconds it'll fallback to the normal website) It's working for me on iOS, could you tell me if you have the Gmail app installed and what OS you're using (on mobile)?