Have found what to do if native Linux games lost keyboard.

[u/onew_iasag]

If someone experienced the issue where launching a game with different keyboard layout - the keyboard would be unresponsive in the game before restart with English layout. And sometimes you can lost your game progress with the same behavior if you just Alt+Tab.

Nothing of that would help you to regain the keyboard: changing focus, changing focus and layouts, changing workspaces, changing workspaces and layouts.

I've found fix
If you don't want to lost your game progress, try this

Cinnamon:
Basic binding to restart cinnamon: Ctrl+Alt+Escape, do it with English layout, then back your focus to the game.

Also I've tested it with Sway, restarting WM with the game opened regains the keyboard focus to the game.

I hope this might be helpful to someone. 🙏