This is a common mistake. You're running searches like
stats values(foo)
when you should be running
stats count by foo
instead. The former will return just one row, with "values(foo)" as a multivalue field. However it is designed for situations when there are only a few values, so it truncates at 50. The latter on the other hand will display any number of rows - hundreds, thousands, millions, and never truncate.
Similarly, if you find yourself doing stats values(foo) by bar, intending to get unique combinations of foo with bar, just do stats count by foo bar.
You could also just do top 0 foo bar.