Just attempted now to repro and appears to be fine on my end.
When was the app created, was it recently? If so I would advise the following:
- Test the share in different browsers
- Confirm if cookies are enabled in browser (including 3rd party)
- Clear cache and attempt same execution in incognito mode.
If with this you still face this issue, unless the app is recent (which then i would advise to wait a few days, as mine now is able to be shared). My suggestion would be to reach us via support ticket so we can investigate what is going on here in more detail.
Regards,
Ricardo