Hi, Stephanie!
Let me see if I understand this problem correctly. You have two columns of "label" data, and you want to sort them alphabetically in a table. When you do try to sort them, the first column sorts correctly only through the letter 'D', and the second column sorts correctly only through the letter 'R'. Am I understanding this correctly?
I had a similar problem in one of my tables, and it turned out that there were non-printing (i.e., "invisible") characters scattered throughout the data. These non-printing characters were messing up all manner of things, from sorts to calculations to matches. I ended up using the ReplaceRegex() function in the transform pipeline to remove the offending NPCs from the original data columns.