I installed 'Arc Dark' theme, and activated. It changed all my 'panels' and the things into blurry-transparent that used to dark on Breeze Dark theme (panel, menu, notifications, etc).
I really didn't like it, so I just changed it.
But, it keeped the blurry-transparent, and I dont like it.
I tried deleting plasma/kde folders on
/usr and more.
Reinstalled multiple times plasma/kde packages, but nothing.
Running kinda fresh install of Arch Linux.