At a guess, maybe the browser is using the GPU acceleration from Intel and not the Nvidia GPU.
Nvidia GPU acceleration will be less problematic, I would check in Windows settings, Graphic Settings and look for Brave and ensure it’s using the Nvidia video card.
Tested in new profile, I wasn’t able to reproduce this on my end (2 different machines, 1 laptop and desktop.) Using Nvidia 2080S 466.27 Driver (Desktop) and AMD 20.10.32 / 1660 Ti Nvidia 461.09 (Laptop).,
Would update the graphics driver, and test in a new profile.