Problem with verification (in incognito?)

Hi guys!

Following Josh's tutorial, I implemented user verification on my site and everything works great, but only up to a certain point.

When user tries to verify the account using Gmail or email application on Android, then the page starts inside the application (kind of like in incognito window) in this situation on the page there is no proper button to verify the account, but full registration/login form.

How it should like: https://a.cl.ly/KouJY6e4
How it's like: https://a.cl.ly/DOuBmYv4

Unfortunately, this form does not work, because the user has already added an e-mail to the database, but he also cannot verify himself because his account has not been activated.

Any ideas how to deal with it?