5.30 Full screen area not being used.

I have had ROS 5.28 running on a Pi400 at 1920×1080 without a problem on my monitor. However, I have just tried 5.30 straight off a new SD card and the desktop does not fill the entire screen. There is a black border around the edge. On changing the resolution it seems to always scale to the same bordered area regardless of the resolution setting. Any idea what might be causing that. The screen settings shows my monitor model number correctly.

Ensure that the textfile !Boot.Loader.CONFIG/TXT has the line “disable_overscan=1”. If it doesn’t use a text editor to add it.

Perfect, thanks!