I can confirm the issue. When I click “Login with Google” in the app, a pop-up appears that asks me for my Google credentials - regardless of the existing sessions in my browser. I will not enter my Google username/password into some app without a visual confirmation that the form is delivered by Google. In this case, it may as well be a phishing attempt. Even the fact that I use 2FA does not improve this situation.
The user experience should go like this: open the app, click login, a redirection through a normal browser tab appears, choose login, get directed back, login successful.