I don’t have a Star, but in the UnitiCore which has similar firmware, you can clear that message in the app (Core doesn’t have a display) by tapping the “clear results” link at the bottom of the screen.
What I have on the uniti star is an “OK” to tap within the Ripping Monitor on completion. All this seems to do is return the app back to the home page but the display remains the same.
“Turning it off and on again” via the front panel button doesn’t actually turn it off. It just puts it into a standby state, which state it is depends on how long you press the button, as explained in the online instructions. If you pull the power, wait a few seconds and then plug it in again, then you have done a proper power off restart.
But I haven’t heard of this issue before. I suggest you might try a factory reset, following the online instructions. If that doesn’t work you will have to ask your dealer to sort it out, or contact Naim technical support yourself to ask for help.