A family of Microsoft relational database management systems designed for ease of use.
You need to design your report to expect a varied number of columns since that is what a crosstab query returns. You can't define a report based on the columns returned by your initial query trial. The results will change as your data changes.
Trying to output a crosstab query to a report is probably not a good idea to begin with, because your columns will most likely exceed the paper size. If you need to output your results for others, you might find that it's easiest to export your query results to an Excel file.