One of Android Oreo’s many new features is a persistent notification for each app that runs in the background. While this is certainly helpful for the average person, it can get old quick for power users that frequently run applications like Tasker and LastPass. If the messages really get on your nerves, you can now use Tasker and the Notification Listener plugin to hide them.
You can view the whole instruction guide at XDA, but it involves installing both Tasker and Notification Listener (linked at the bottom of this post) and importing a Tasker profile.
Tasker can hide Android Oreo’s ‘App is running in the background’ notifications, root not required was written by the awesome team at Android Police.