Was running trains yesterday, when for no obvious reason, trains on TIU 3 became unresponsive. Traced problem to TIU renaming itself from TIU 3 to TIU 1. Obviously having 2 TIU's named TIU 1 doesn't work. I attempted to rename the original # 3, 3 again, and received an error message "TIU ERROR" I tried renaming it 4 and 5. Same error. There are 2 independent loops on the TIU, and it is powered with a separate Z500. Each of the 2 tracks receive power from a Z4000. There were no derailments during the session. I have repowered the 2 loops from another TIU, and have no issues operating the tracks on this TIU.
The troubled TIU does have power, just will not rename back from it's self assigned name.