1993 E36 no ignition BUT power remains ON

I have a 1993 325i sedan with 237K. I recently started it and moved a few feet and turned off. When I removed the key the power to display, lights, exhaust fan remained on. (power steering was not active). When attempting to restart with key, no ignition but power to car components as above stayed on. Disconnected battery. No apparent issue with ignition cylinder or spinning key. Lowered steering column shroud, removed grub screws and removed ignition switch to test with screw driver (as described in forum by hanzandfranz). Same result. Novice question - from the description above, is it likely the ignition switch(?), ignition assembly(?), possible electrical issue(?) or more complex? Any advice on how to more properly diagnose is greatly appreciated.

Recent work included some shop work in which wiring harness splicing to the windows and sun roof was performed.