Command key tight to an unknown function

I am using macOS Sequoia 15.5 on Macbook pro M3 and I'm new to mac.

My command key makes an action that I can't recognize by any name, and can't change it. I'll explain what it does:

When clicking on command once(not holding), all the open windows slide outside the screen and a black semi-clear border is portraid around the screen and the desktop items are shown(you can see it in the screenshot attached).

In this situation, if clicking on the command key again, it returns to the previous step.

I wan't to remove this action; when I want to copy/paste, the window I am copying from/pasting into slides outside the screen when I'm clicking on the command key. It makes me nuts. I searched for a solution, used AI, but nothing helped.

Few key hints:

1. I don't have 3rd party keyboard mapping managers
2. It is not related to state manager view

[Edited by Moderator]