How to display all open apps on one screen in macOS Tahoe?

A bit unclear, but the relevant settings are in System Settings > Desktop & Dock. Turn off items relating to Stage Manager and Spaces.

Iva818 wrote:

I just upgraded to Tahoe.

My desktop screen used to keep everything I had open and that was in process (chrome, email, documents, etc) on the same screen, stacked up or I could arrange them as I wanted.

Now there are two groups that are sliding on and off, left-right, so I have to re-click the app on the dock, email for example, to get that open inbox back onto the screen. It's driving me crazy. How can I adjust the settings to show everything on one screen, as it had been?

[Re-Titled by Moderator]

Original Title: Desktop/Screen in Tahoe

Save your self the headaches

Turn off Stage Manager and put the apps in full screen

Mission control you see all full screen apps

ref: View open windows and spaces in Mission Control on Mac

Command Tab displays the HUD (Heads Up Display) of all open app; usr you mouse or Tab through to your selection holding the Command key down...

It sounds like you have created a second Desktop in Mission Control.

It will only show what is open on each Desktop. Note also that apps in Full Screen will each be in their own Desktop.