Dorico 5: Dragging pattern from Groove Agent to Key Editor does not work

It looks like it should work, but nothing sticks to the key editor. Gets the + sign and a barline when dragging, but nothing sticks.

Works now! Did not choose Playback template.

It doesn’t work for me either.

Define “work” please.
What do you see or not see that you expect?
Do you have a note in the key editor to activate the grid (make it appear rather than be blank)?

If you’re dragging material in to the percussion editor and nothing is appearing when you finish the drag, it is most likely caused by Dorico not knowing what percussion map you expect it to use. The simplest way to tell it, as Jonas says, is to use one of the built-in playback templates that sets everything up for you automatically. If you want to set things up manually, then you can go to Endpoint Setup in Play mode and choose Groove Agent SE Studio Kit under the Percussion Map column.