I'm not sure why you would want a notification to be silent. That seems to be an oxymoron.
Here's what they were:
What's that picture of the phone at the top supposed to illustrate? There's no legend.
What do the sliders beside the "Silent notifications" do? Does sliding them to off make the "Silent notification" not silent? Does it clear the notification?
This is a beta.
9to5Google's article on this begins "Android's notification system has been pretty great for a long time now..."
But I guess I'm not a big user of notifications.
Android Q Beta 5 fixes this in one fell swoop by labeling notifications as "Alerting" or "Silent" and splitting up the notification shade as a result. Notifications that are set to "Alerting," the default for most apps, will appear at the top of the list of incoming notifications. Any notifications set to "Silent" are dropped below a clearly labeled section. The section also has its own button for clearing only those notifications.So if you have a BIG problem with notifications on Android, Q should help.