External monitor - display is too wide

[oygle]

Operating System: Kubuntu 25.04
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.12.0
Qt Version: 6.8.3
Kernel Version: 6.14.0-24-generic (64-bit)
Graphics Platform: X11
Processors: 4 × Intel® Core™ i5-7300U CPU @ 2.60GHz
Memory: 7.6 GiB of RAM
Graphics Processor: Intel® HD Graphics 620
Manufacturer: LENOVO
System Version: ThinkPad T470s

1. External monitor - From the plate at the back of the monitor, it is a Lenovo T2254pC , however it seems from searches it is T2254p
2. Booting to the internal SSD and windows 10, the monitor works fine, position wise. Can see the full vertical/horizontal aspects.
3. Booting to Kubuntu, from the external SSD, I can see (external monitor) approximately 97% of the vertical aspect, being able to just view the top of the task bar. The horizontal view is approximately 80% , so there is about 20% missing from the RHS.

Have tried using the ‘menu’ accessible from the front of the monitor. menu options appear but using either ENTER, or left or right arrows does nothing.

Have used the ‘display’ option under system settings to no avail. The resolution is correctly set as 1680 x 1050. If I attempt to change resolution, refresh rate, global scale, etc , often I either loose the external monitor or the display connected to the laptop.

Have spent many hours searching and trying ‘xrandr’ and other tools, often loosing eithher of the displays, and it takes several reboots to find the external monitor again.

I’m using XOrg not Wayland, the latter is too unstable.

So, as an overview, if the display works perfectly in Windows 10 and not in Kubuntu 25.04, then surely it is drivers ?? (Have attempted to ‘add’ nvidea drivers, and that was a mistake, as the graphics card is Intel not NVidia.)

The attached screenshot shows what I can see on the external monitor

[oygle]

I checked the “Display” BIOS settings. It was set for a Dock situation, so changed it to HDMI. Rebooted, no change at all.

I had always used the System Settings/Display to try to adjust settings, however none of that worked. So, used a function, found on the task bar called “Display Configuration”. . It had 5 options, then selected the one shown at https://imgur.com/a/kubuntu-display-configuration-using-external-monitor-MEWBdOf and I can now see the full screen and task bar. Finally it works.