@AndrewM114DD
Unfortunately, ShowColumns, SortByColumns and a couple other functions still require the real field name to be used.
The inclusion of using the defined name over the real name is only within the past 2 years. Before that you always had to use the real name for everything.
There used to be a feature to turn on and off to allow formulas to use defined names, but that feature was eventually just turned on by default and disappeared. However...that feature still only applied to the functions that supported it (Filter, Distinct, Choices, etc.) The ones mentioned above did not honor that setting even back then...and they still don't.
I hope this is helpful for you.
