iOS, Android?
Versions of phone, Blynk Library, App, etc?
Are you using share or clone? They are different.
Depending on the other person, you may find it simpler to just have them use the same login, then they have full access to all projects.
Open the email on a PC and use the camera phone that way 
(assuming of course the QR code shows… get us the rest of the info and take it from there)
PS, I moved you into your own Topic.