@burnout426 I don't know what helped, but it worked!!!
The standalone version worked fine... Then, in the Opera that I used to use, I deactivated all Extensions.
And the Gmail standard view worked!!! But now, I reactivated all the Extensions again, and is still working '-' So I know where the problem is, but it's not affecting me anymore...
If Gmail stops working again, I'll know what to do... And it's easier than cleaning the cookies...
Thank you man, you helped more than anyone else!! ❤