How to install drivers for graphic card Radeon AMD Ryzen 7 VGA Picasso

I got a Lenovo Ideapad L340-15API and the webpages are not displaying correctly either in mozilla or chromium. They display centered in a limited area. Also the general size of all graphics and fonts in Ubuntu 18 is reduced. I tryed by changing the screen resolution size, but didnt work. I want to check if the drivers ar OK to thiscard this as a possible reazon or fix it. Thank you.

This is what comes after inxi -Gx:

Graphics: Card: Advanced Micro Devices [AMD/ATI] Picasso bus-ID: 03:00.0 Display Server: x11 (X.Org 1.20.5 ) driver: amdgpu Resolution: [email protected] OpenGL: renderer: AMD RAVEN (DRM 3.33.0, 5.3.0-26-generic, LLVM 9.0.0) version: 4.5 Mesa 19.2.1 Direct Render: Yes

You can see in the attached immage how the web pages are displaying

Does this makes any sense?

Thanks!