Excel import wizard is very useful, but if your first row is blank it will sometimes treat the column as numeric and empty the data. Changing the column type in the wizard (JMP 17EA) doesn't cause a re-import, and running the table macro with the column specified as character doesn't solve the problem (appears it imports and then changes).
Suggestion: either allow 'import all columns as text' (or perhaps 'preserve all cell contents'), or something that allows you to restart the import process after assigning data types to columns.