Zkus:

The easiest way to fix this is to block the notification from showing. There are two ways to fix this.

First method

Go to your notification and long press the persistent notification.
Tap ! mark on the right side. That will take you to Settings
Select Block and turn it on.

Second method

Go to Settings → Apps
Select the app with the persistent notification
On the same screen select Notifications
Select Block and turn it on.