For most window types, no close icon (or minimize or restore) is displayed.
However, when I open the table editor, I see the icons for this window on the right at the level of the menu. Minimize and resize have no effect. Closing works there.
I'm using SDI with the settings "Don't show Tabs", "No Use multi-row tabs" and "Close button on tabs". Windows are usually maximized.
[Linked Image] sql window without [X]
[Linked Image] table editor

Can you let me know your Windows version?

I use Windows 10 Pro 21H1 64Bit
The attached video for this post link shows the described behavior

We cannot reproduce this. Can you let me know which window types display the [x], and which don't, so that we perhaps can find a common factor that is causing this?

If you choose SDI with no tab, none have close buton.

yes I agree with fabrice. Here are some more pix to illustrate...

[Linked Image] SDI with "Don't show Tabs" and Close button on tabs "Active" or "Active + Hover" or "None" or "All"
[Linked Image] SDI with "Tabs on Top" and Close button on tabs "Active" or "Active + Hover"
[Linked Image] SDI with "Tabs on Top" and Close button on tabs "All"
[Linked Image] SDI with "Tabs on Top" and Close button on tabs "None"

This also a font color issue? On my screen these icons are white and the background is light grey. The icons are hardly visible...

Thanks! We'll investigate.

see also the last movie in this post.