Hi,
We have investigated why OpenGL HW acceleration is disabled in Chromium and it is because Chromium deb packages are shifted to Snap in Ubuntu 20.04 onwards. We are now working with Canonical on figuring out why OpenGL is not working for apps through Snap . It is tracked in
Bug #2028864 “[snap] chromium browser does not work with acceler...” : Bugs : chromium-browser package : Ubuntu
As a quick solution, please get deb package from:
Packages in “chromium” : chromium : Nathan Teodosio
And give it a try.