Should be fixed in v5.10.0.1 beta, please try it.

See also this thread.

Please provide more details:

• What is your version of 7+ Taskbar Tweaker?
• What is your version of the explorer.exe file?
• Do other tweaker options work properly?
• Try to recreate a simple scenario as shown in the video here. In this simple scenario, does Notepad keep its order?
• If possible, upload a video that shows the problem.

Can you please specify your version of 7+ Taskbar Tweaker and your version of the explorer.exe file (in file properties)?

Perhaps you're using a vertical taskbar?

This option doesn't have effect on a vertical taskbar.

For Office apps in general, and Word and Excel in particular, I heard a number of complains about non-standard user experience behavior. See this comment, I believe that's the issue you're seeing. That's how Office was designed to work, and I don't plan to work around this with the tweaker.

I'm not sure what's about "Power Director", but I believe that's it's a similar situation in which a new window is created.

You might be able to mitigate this behavior by not disabling grouping or by using the option:
"When not grouping, place new items next to the existing ones"

I'm not sure about the "Cannot open library 5" message. If you know of a way to reproduce the problem, please tell me.

Regarding the combining issue, see the discussion here:

https://tweaker.userecho.com/topics/329-decombining-options-dont-work-as-expected-with-the-combine-when-taskbar-is-full-configuration

Closing as a duplicate.

Great, so I did understand it correctly when I closed the topic the first time.

Great, I'm glad that you solved the problem. The Windows spacing options are new to me as well, good to know about them.

What does "don't group pinned items together at all" mean? The help file describes the option in more details, and provides an example.

From the help file:

Don't group pinned items
Every pinned item has an Application ID, just like the taskbar buttons. By default, when a taskbar button with the same Application ID as the pinned item is created, it replaces the pinned item. This option makes the taskbar button show up at the end of the taskbar, while the pinned item stays untouched

For example, you have a pinned item of Notepad:

By default, when you create a Notepad window, you get:

With this option set, you get:

Note
It's possible to control pinned item grouping per Application ID using Taskbar Inspector.

How is that different to what happens with the "Don't group pinned items" option?