The Arduino code shown runs successfully. My problem is configuring the Arduino IDE so it fits within the Raspberry Pi window. The second image, the built-in serial port /dev/ttyAMA0, is produced. It is blank.
The Arduino Menu bar cannot be accessed. Therefore, the Tools button and other buttons for running the code are not available. The user can adjust the width of the Arduino IDE window but cannot move it around the screen or up or down.
The /boot/config file is setup up for a Adafruit 5" Backback monitor. No other app, Thonny Pi, or the terminal has these problems.
It appears to me that the config file needs some work. That is only a guess.
Any suggestions will be greatly appreciated.