Ubuntu – Ubuntu 20.04 lag issues

I am using DELL Latitude 5495 with AMD ryzen 5 pro . I accidently updated from 18.04 LTS to Ubuntu Focal Fossa 20.04 (development branch) instead of LTS.

I have been facing a lot of lag/freeze issues very frequently. Pixelation of graphics is noticed and Cursor and keys freezes for a few seconds mostly while using a browser/application. Seems to get better temporarily with reboots.

How can I resolve these issues or shift to the LTS version of 20.04/rolldown to 18.04 LTS to avoid them without losing data? (I am fairly new to linux)

It is similar to Random temporary screen lags since upgrade to 18.04

The results of sudo lspci | grep VGA && sudo lshw -c video | grep configuration && glxinfo | grep -i vendor are:

04:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Raven Ridge [Radeon Vega Series / Radeon Vega Mobile Series] (rev d1)
04:00.7 Non-VGA unclassified device: Advanced Micro Devices, Inc. [AMD] Raven/Raven2/Renoir Non-Sensor Fusion Hub KMDF driver
       configuration: driver=amdgpu latency=0
server glx vendor string: SGI
client glx vendor string: Mesa Project and SGI
    Vendor: X.Org (0x1002)
OpenGL vendor string: X.Org

edit 2:
In my case, It wasn't an issue with the drivers or swap,
I downgraded the linux kernel from 5.4.0.12 to 5.3.0.28… works like charm!