After a random reboot my "forward" orientation got spun around and moved the guardian wall, almost as though settings had reverted to a previous positioning I had. For the life of me I couldn't find a way to correct it, so eventually ran the full set up again. I believe the section where you position the sensors finally set this correctly, but I can't complete that process because it wants the sensors so close together that my play area won't support it. I had to set the direction, skip the rest, then reset the guardian wall. All is good now.
It would be good if there were a simple way to just reset the orientation. Setting the floor height, other calibrations, even restarting into classic mode to "Reset View" didn't work. If I missed something please let me know.