Sort by Custom List Not Working

I have a report I receive that I can't change the way the layout is exported, but I need the columns in a different order. I created a custom list with the column names in the order I need them. The list appears to have imported correctly, and when I type in the first value in the list, and then autofill down, the list autofills exactly the way I expect.

When I try to actually use this list to sort with however, it looks like excel is only taking the first 14 or so values, and then is sorting the rest of the columns alphabetically, ignoring my custom list.

I've got a workaround in the meantime where I create a new sheet, autofill the list in the order I need, add a helper row to my original sheet with a match function to get the row number from the workaround sheet. I then can just sort by number smallest to largest. But I'd like to be able to do the sort without the extra steps.

Im on Office365 for Mac

Sheet attached. Worksheet named "Original" is the columns how I receive them, and "Order" is the custom list I'm trying to use to sort them.