failed to limit the number of results when using group by in TDengine

Question

I want to limit the result of a query in TDengine. My sql statement is as follows:

SELECT last_row(*),tel_device_id FROM geo WHERE account_id_cp IN (...) 
GROUP BY tel_device_id LIMIT 2000

However, the result is more than 2000. I cannot tell how to solve it.