The platform is handling "/default.aspx" and "/Default.aspx" differently and when a Home Page shortcut exists "/Default.aspx" renders an empty screen.
The platform returns "/Default.aspx" in certain scenarios (in our case, after a login redirect) and we need it to respect the Homepage shortcut similar to "/default.aspx".
1) With no Home page Shortcut
https://[domain]/default.aspx -> https://[domain]/default.aspx -> renders Home page, expected behavior
https://[domain]/Default.aspx -> https://[domain]/home?/Default.aspx -> renders Home page, expected behavior
2) Set Home page shortcut; Home>Properties>Advanced>Shortcut - select Products page
3) With Home page Shortcut
https://[domain]/default.aspx -> https://[domain]/products -> renders Products page, expected behavior
https://[domain]/Default.aspx -> RENDERS EMPTY PAGE, THIS IS OUR ISSUE