Hi.
So in our Magento solution we have implemented our SSO login. Only customers who are registered with our SSO solution will need to use our Magento store. Because of this we removed all other options from the login page but a "sign in with SSO" button.
However there is one place where the old login still appears: during checkout. If the user start shopping without logging in, add an item to his cart, and tries to checkout, a window will appear with a login form.
We want to remove this from appearing under any circumstances. Ideally replacing it with a redirect to the login page where we have the SSO login button, or add the SSO login button there. However, I cannot find out where to do such a change.
This is related to another issue we have. Even after users login, they don't seem to appear fully logged in (even though they can access their profile and such). When they add an item to their cart and tries to checkout, Magento treats them as if they are not logged in, showing the window with the login form. This stops after users add an item to their cart and then refresh their page or move to another page. I don't know what causes this either, if its due to our SSO or not, but it happens consistently.
Any ideas on how to do what I mention and also maybe how to fix that latter problem? We are using Magento 2.3.2 and PHP 7.2.24 on a Ubuntu 16.04.6 system.
Thank you for your time.
