I think its mostly a problem in that login screen. At least SAP version I tested seems to find most elements when logged in to SAP. But I get the same problem that I can't get other than the Pane in that login screen. It might be for security reasons that SAP doesn't give other elements than that in the login screen.
So I would recommend to use Launch SAP -action and giving the login credentials in that it just opens the SAP right away so you can skip that window.
If that doesn't work you could try using Run application where you can give the login credentials in the Command line arguments.
Article about it: https://learn.microsoft.com/en-us/power-automate/guidance/rpa-sap-playbook/creating-sap-desktop-flow-vbscript
If that isnt possible you could try the Recorder to do that.
Although since it most likely only finds the Pane it will take that element and in Advanced give Mouse position relative to the element. So that might fail if the size of the window or resolution is different (like in Unattended run it might be).
You could try "Move mouse to image" for example.
