Hi, I was using a amd ryzen 5 3400G APU and it worked fine, till an update in December / Januarysh, after that I am unable to watch any youtube video, and also some sites without getting major graphic artefacts, that just become larger colourful triangles, all over the video, and the entire interface, it happens couple seconds into playing a video, or minutes... I read somewhere that the IOMMU is the issue, but I cant seem tot access it via the bios.. one suggestion was to modify the grub, based on this site: Graphics glitches and artifacts with Ryzen 5 3400G APU - Ask Ubuntu
they suggest making changes to this part:
"quiet splash iommu=pt"
How do I do that exactly? New to this OS, could use some guidance, step by step ... Thank you!