I do not know how to formulate this question, i would like to remove this kind of card/notification. When clicking on the button "Clear" the other disappear but not the one you can see on the image.
Look like it's blocked, look like kind of RSS, i do not reminder what i clicked from Firefox but it's there since few months.
Settings > Notifications, then disable all do not change nothing. Then I do not see the cross to delete on hover.
How to force clear this?