Well I called MTH customer support today,
and there is a way to reset the address to factory default 3.
set the engine on the main, 
select loco 55
enter
program on main. 
program loco 55, 
CV 55 with a value of 55.

exit out and call up loco 3,   perform start up and it should work.

If you want to re enable long addressing 
at this point, go back into programing for loco 3, 
at CV29 enter a value of 38.