I may not have understood correctly what the option: "Preferences>User Interface>Appearance>Show window connection in application title" is supposed to do.
At least I didn't notice any change in the application title. In both cases, user@database is shown.

I may have overlooked a setting. But in v15, title 2 shows the current window. In addition, the title is centered, in contrast to v14, where it is left-aligned.
The picture shows v14 in the background.
[Linked Image]

When enabled, the connection of the current (topmost) window will be included in the application title. When disabled, the main connection will be included.

As long as the topmost window uses the main connection, you will indeed see no difference.

Ok, I use the "Dual session" mode. Therefore, this option seems to have no effect.
But what about the 2nd part of the question? Double display of the window name and centered display? (see image link)

The centered title is normal. On Windows 7 it may previously have been left-aligned.

The double file name I cannot yet reproduce. We'll look into this. Can you let me know your Windows version?

I use Windows 10 Pro 21H1 64Bit
As can be seen in the picture, both versions (v14 and v15 beta) run on the same operating system.
I use SDI without tabs.

Okay. We'll try to fix this for beta 2. Perhaps you can verify this when beta 2 is available later this week?

Of course, with pleasure ...
Sorry for always reporting only problems. I think you are doing a very good job. That has to be said too.

I strongly disagree! I use Windows 10 20H2 and most applications display the title left aligned!
I use PL/SQL developer via remote desktop and the application title is completely obscured by the remote desktop connection bar on top.
Version 14 displays the title left aligned, too.

BTW, the icon to the left is not centered vertically, it's aligned to the bottom of the title bar.

Yes, the title is still centered. I would really appreciate a left-justified display option.
The problem with the double display of window name is solved.