Mac OS: Stalled / Freezes and blurry screen after some minutes


I have a strange behaviour on my Macbook Pro late 2011 with OS Sierra.I have a 500GB SSD, 16GB RAM.
Last week I installed the latest version of Brave 0.18.29.
Installation went fine but when I start Brave, my Mac stalled / freezes for about 1 minute (black screen)
I can do nothing… After 1 minute my Mac rebooted automatically.
After the reboot, I have to reset the NVRAM. Otherwise my mac cannot continue.
I’ve tried to disable the hardware accerelation in Advanced Setting but no avail.

I tried another method to see what will happened:
I installed gfxCardstatus app on Mac ( With this app you can switch the between the 2 graphics cards in the Macbook. After I switch the graphics card to Discrete Only I started Brave again.
Now after some minutes the screen is divided in 2 pieces and it is blurry. :open_mouth:
After pressing Cmd-Q Brave quits and the screen is normal again.

I’ve already tried to delete cache, gpucache, re-installed different versions, etc.

Any idea ?