I have an application that runs in desktop and VR. If I start the app in desktop mode and put on my headset, the Oculus app launches and after a few seconds, my app starts to render in the HMD. A few seconds later, Oculus Dash appears and steals input focus. If I select my application from Dash, it returns focus to my app. If the Oculus app is already running when I switch to VR, this doesn't happen (my app maintains input focus).
I tried the same series of steps with an app like Quill. I see that Dash does appear when the Oculus app starts, but then focus is returned to Quill and Dash disappears.
As far as I can tell, I'm following all the advice from https://developer.oculus.com/documentation/pcsdk/latest/concepts/book-dg/