I've been programming on octave for some months, and I usually use the GUI that separates the command window, but when i run a script, the black command window closes, and the one from octave glitches and flashes weird symbols and colors, and when I resize it the symbols change.
I updated to the latest version of octave and nothing changed
I assume you are running Windows 11. Somewhat recently, Microsoft developed a new Windows Terminal that is included with Windows 11. A recent Windows update has switched it to be the default terminal. Octave’s GUI command line interface uses the host operating system’s default terminal, but it appears that there are incompatibilities between the new Windows Terminal and the old Windows Console Host. It is causing numerous issues, including additional windows appearing, crashes, and garbled characters appearing on screen when scrolling.
As Octave is crossbuilt from Linux, there is a limited developer base (with Win11 and the new terminal to use for debugging) available to work through these issues. The only reliable workaround right now that has been posted as a general solution to the Octave Help Discourse forum is to change the Windows setting reverting the default terminal to the Windows Console Host. That post points to Microsoft's instructions for finding and changing the setting in Windows. (Note that this setting for a default terminal only applies to Windows 11.)
In addition Octave has recently added warnings to the program installer that recommend changing the default terminal system setting if you are running Windows 11 to avoid these problems until a solution can be found.