Thanks for your report.

gjanik wrote:

Problem 1: Can't seem to open multiple simultaneous sessions to multiple servers. There is no error, but previous versions showed individual icons for each session/server in the bottom Windows bar. Now there is only one session icon, the most recently opened one.

How are you opening session? I guess that using Jump List or desktop shortcut.
Recent version open sessions using an existing instance of WinSCP if possible.
So you will see multiple tabs on your WinSCP windows (similar to Web browser tabs):
https://winscp.net/eng/docs/ui_tabs
If you do not like this, you can make WinSCP open session in new instance by holding down Shift key while opening the session.
Option to revert to previous behavior has been added to the tracker:
Issue 1099 – Optionally open additional sessions in new instance

Problem 2: When opening a new session, focus does not move to the new password entry box. I have to click on the menu before I can enter the password.

I suppose that happens when WinSCP is opening second (and later) setting in an existing instance, right?
This issue has been added to the tracker:
Issue 1098 – When externally opening additional session in existing instance of WinSCP, bring its window to front

Installed version 4.4 since 5.18 is no longer available. Everything works like it used to on 5.18.

You can get any version you want from:
https://sourceforge.net/projects/winscp/files/WinSCP/

I recently upgraded to 5.5 from 5.18 on Windows 7.

Problem 1: Can't seem to open multiple simultaneous sessions to multiple servers. There is no error, but previous versions showed individual icons for each session/server in the bottom Windows bar. Now there is only one session icon, the most recently opened one.

Problem 2: When opening a new session, focus does not move to the new password entry box. I have to click on the menu before I can enter the password.

Installed version 4.4 since 5.18 is no longer available. Everything works like it used to on 5.18.