It seems Opera for Windows 94.0.4606.65 has a default keyboard shortcut for exiting the browser that is defined as Ctrl-Shift-X.
This is the same shortcut used by the 1Password extension. It seems the default browser shortcut triggers first so Ctrl-Shift-X always exits the browser.
I have tried to undefined the Exit shortcut (Settings > Shortscuts > Click "X" to remove it") but then Ctrl-Shift-X does not do anything anymore. It does not exit the browser but also doesn't open 1Password.
1Password Version: Not Provided
Extension Version: 2.5.1
OS Version: Windows 11
Browser:_ Opera 94