Pressing Alt+Tab causes Microsoft Edge's to switch into tab rather than app

tl;dr Sometimes when I hit Left Alt+Tab in Microsoft Edge, I am switching to another tab (like I'd press Ctrl+Tab) instead of switching to some other app in Windows 10. This is terribly annoying and counter-productive. What is causing it (is this a bug or yet another Microsoft invention) and how to get rid of this?

I've been using Microsoft Edge for years on many PCs. Always without any problems. Since yesterday I have a brand new PC and I am getting and awfully weird experience in Edge. When when I hit Left Alt+Tab, instead of switching to another active app, I am rather switching to some other tab in Edge itself.

A closer look told me that for some reason beyond my imagination, my Edge shows some (but not all!) of my tabs as a separate tasks / processes / apps. And most likely this is causing all the problems.

An example -- Two of five Edge's tabs are shown as a separate windows:

When there are two Edge's windows opened up intentionally by user then things gets even worse. Here:

you have an Edge with:

• 15 tabs opened up in first window
• 1 single tab opened up in second window

Instead of showing (as expected) two elements in Task Manager, I can clearly see... seven items. For some reason six of fifteen tabs opened up in first windows are seen by Windows as a separate apps or tasks running.

This drives me crazy and actually causes any reasonable work with Edge completely impossible. Is there any explanation for this behavior? Is there any solution?

Solution 1:

Open the Windows Settings app and go to System → Multitasking. Find a setting labelled "Pressing Alt+Tab shows":

And select "Open windows only".