LCD Touchscreen not working

Hello,
I bought a Waveshare Touchscreen:

When I connect the Screen to the Vim1, it shows random pixels, like the screen is broken (it is not, I tested).

Is there an issue with LCD? Or the hdmi driver?
Thanks for your help.

Fabian

Update:
It is the resolution.
400x1280 is actually needed. How can I add the resolution in the Ubuntu Xfce?

Hello @Fabian_on_Security

Which image you used?

The newest I could find:

vim1-ubuntu-18.04-xfce-linux-4.9-fenix-1.1.1-220725-emmc.img.xz