Notification are currently provided by 'KDE plasma'

I have problem with my notifications, my notifications are currently provided by 'KDE plasma' and I can't fix it

Look at my setting:

Look at my notification bar:

I try that too:

In here i unable all of applications show notification in don't disturb mode but he's not work too👆🏻

My version of Kubuntu is this:

I need your help for fix this problem :)

I'm late but I just solved this problem minutes ago. I removed from my desktop all widgets/plasmoids/interactive elements that could display notifications (I also disabled the notifications in the system tray just in case) except the notifications widget, which I wanted to use.

After that I rebooted to restart plasma and everything was OK.

It was this post that helped me.