Clicking the red X icon normally closes just the current window, but when you click it, it closes all windows?

The keyboard shortcut Ctrl+w (close tab) should work to close a window when it only has one tab open. You could try that as a workaround until we figure out what's going on with your red X button.

Yes, when I click on the red X it closes both windows. I'll try the Ctrl+w Thanks

Ctrl+w worked in closing one window and leaving the other one open. I'll try and remember that until the red X gets resolved. Thanks again