Okay. Not on my mobile app but on my desktop. When you are logged in, under your messages tab, you will see the number of notifications or messages. It will then refer you to your dashboard. This is where you may see them including references to reviews etc. On the right hand side of each is a tiny X. Just click on this to delete the notification. Sometimes this notification may be a message from AirBnB about something like “did you know you can embed your …” ie, a helpful message which is still a notification and will still stay there until you click the magic X.
Can’t show you a screenshot as mine are all deleted. Try this, then they should disappear from your mobile app. At least I hope they will! 