I did a fresh install of Ubuntu 20.04 on a Matebook X Pro with only Intel integrated UHD Graphics 620.
Freeze happened when trying to add a new GMail account, and also at various other sites.
When I write incredible fast in search/address line the text appears unevenly with a small delay.
Also text input in browser (like where I write this) is a little bit slow, delayed, but only noticeable as I have repeat keys set very high).
I've found several years old similar treads that recommends to disable GPU acceleration. I tried it but still incurred freezes.
I tried both Chromium and Chrome and both had the same issues.
I tried Firefox and it also froze when opening many youtube videos. Whole machine froze for about 2 minutes before going back to normal. While that happened, this https://askubuntu.com page, that was open in Chrome, crashed with the following error: