Ubuntu Mate 20.04 live usb disk fails at desktop image

I downloaded the iso image from official site, I created a USB bootable with the standard tool on my Ubuntu Mate 18.04 desktop PC.
When I try to start the desktop PC with the bootable usb disk I can't do nothing because the image is what you can see in the attached image. The same usb works perfectly on my Acer laptop.
My desktop PC has a LG monitor 23" 16:9 connected via HDMI connector.
Graphic card is Radeon Vega integrated in Ryzen 3 3200 G processor.
monitor image mess

A post was merged into an existing topic: 20.04 Display issues with AMD GPU