That didn’t work for me, but a hard reset returned my cruise and autopilot. Potentially the emergency braking, too. I still have the Online Routing Disabled error, though.
HARD REBOOT
Open the frunk, front driver and rear passenger doors.
From the Controls screen, go to Safety, Power Off. Power off.
Remove the plastic air intake shroud just in front of the wipers. Pull, and it snaps off.
Remove the air intake funnel. It too is held by plastic snaps.
Disconnect the positive cable from the 12 volt battery terminal . Use a 10 mm socket or wrench.
Reach about 10” in from the back seat edge where it meets the carpet and pull the lever there to the outside while lifting the seat cushion. Do this on both sides.
Lift up the front corner of the seat to reach the styrofoam block on the passenger side.
Lift the block out and set it on the floor.
The high voltage disconnect is a black rectangular plug with a gray release lever on the right side. Flip the lever upwards then pull the plug upwards to disconnect.
The car has literally no power going to the electronics. Don‘t close the doors or frunk.
I let the car sit for 90 minutes before rebooting. This was probably overkill.
Push the high voltage plug back in. Snap the gray disconnect lever down to secure.
Drop the styrofoam block back in place.
Snap the backseat back into place.
Reconnect the 12 volt battery.
Snap the air intake funnel back into place.
Snap the air intake shroud back into place.
You are done. The screen should have booted normally at this point.
All your personalized settings will be saved.
This hard reboot cleared all but one of my (apparent) firmware errors.
All systems appear normal, though I’m not going to test out the emergency braking.