Ubuntu - GPU - Mesa - Install Mesa Utilities - Install the latest stable version of the Mesa driver

To install the most stable version of Mesa than what comes with Ubuntu.

WARNING: This uses a PPA.

WARNING: Installing new Mesa graphics drivers may also require a newer Linux kernel.

It will be a good idea to enable HWE kernel on Ubuntu to reduce the chances of conflict with the kernel.
HWE Kernel gives you the latest stable kernel used by Ubuntu on an older LTS release.

Install the Kisak Mesa PPA driver

The Kisak-mesa PPA provides the latest point release of Mesa.

sudo add-apt-repository ppa:kisak/kisak-mesa
sudo apt update
sudo apt upgrade

NOTE: This will provide the latest Mesa point release.

Edit /etc/apt/preferences.d/kisak-pin-2000, and populate as:

Package: *
Pin: release o=LP-PPA-kisak-kisak-mesa
Pin-Priority: 2000

NOTE: This gives the PPA a higher priority, over the standard.

If you are facing issues and do not want to use the newer version of Mesa, you can revert to the original version.

Install PPA Purge tool first:

sudo apt install ppa-purge

And then use it to remove the PPA as well as the Mesa package version installed by this PPA.

sudo ppa-purge ppa:kisak/kisak-mesa