Brave completely blocks my PC on some sites

Hello, I’ve been using Brave instead of Opera for 3 weeks now. The problem is that some sites are extremely slow and some even freeze the computer for several minutes with the mouse almost not reacting and even a CTRL-ALT-DEL takes more than 30s to complete.

I’ve done a lot of searching, changed GPU flags, tried private mode, new profile, … nothing.
I don’t have these problems with Opera, Chrome or Edge.

Today, I install Brave Beta and the same thing.
I say to myself that I’m going to test it anyway with nightly… and to my amazement, it seems to work fine.

As I don’t want to stay on nightly, I’d like to know what’s been changed and if I can do it on the non-beta version, and if not, how long to wait for this fix to be applied.

Another minor problem is that it takes my RTX4070 by default to go on Brave. I’ve had to modify Windows11 so that it takes the Intel ARC.
Thank you very much.

I9-13900HX, 32GB RAM, Optimus with Intel Arc and RTX 4070