After the newest patch, Vivaldi is very slow. After the mouse clicks or open a picture to new tab, its reacts really slowly, only seconds will happen. Why?
Which Vivaldi version?
Which Windows version?
What means slowly?
Ehm, sorry, no patch (too much gaming), version, and this: 1.9.818.44
Windows is Win 10 Pro x64
Slowly is what I said, after clicking, it takes seconds to react. Before the upgrade the browser worked perfectly.
May be some settings are broken.
Try to reset the Vivaldi profile as described at https://help.vivaldi.com/article/full-reset-of-vivaldi/