I have a mobile app that uses OAuth to login users. That part works really well, but recently I was asked to make it work for SSO (Single Sing-On). The app as it is has a weird behavior. To be able to use SSO the users must input their own domain so they can be redirected to the appropriate login page and once there if they choose SSO, (Google in our case) they are prompted to enter their credentials and log in. All standard so far. However after the SSO auth has finished, the users are not presented with the permissions screen
Furthermore, I have tried the same process with the official Salesforce app and the result is the same, if I login with SSO I'm redirected to the Salesforce mobile website instead of being presented with the permissions screen.
I've been trying to find documentation about it but there's not much for my use case. The only document I found states that the SSO should work the same as OAuth.
This is my SSO configuration
Am I missing something in my SSO configuration? or do I need to do something on my client side to redirect the user to the permissions screen?