@Pastor90
Hard to say.

My PC have several years but everything looks fine.

I use Orera Gx, Opera, Brave and sometimes Chrome.
I only have this issue with Opera Gx and since the last update.

Hello.

On Opera Gx, when I open a new tab, the CPU usage goes up to 30% for almost a minute and then returns to normal.

This only does it on the start page. I tried to deactivate the widgets, it's the same thing, every time the start page opens or I refresh it,

I don't have this problem with Opera browser (no GX) which I also use. The increase in CPU usage when I open a new page is only a few seconds, very far from a minite. Which seems normal to me.

Thanks