My sql query

Hi i have this query but for 100 users i want to get the total users in country and the total order amount of the users but i the issue is when i add COUNT(DISTINCT u.id) it gave me 16 users in USA and when i do it without DISTINCT it gave me 85 users in USA but i don't have any duplication in rows so why this happen please ?

SELECT c.*,COUNT (DISTINCT u.id) as total_users, SUM(o.total) as total_orders_amount FROM countries c INNER JOIN users u ON u.countryId=c.id INNER JOIN orders o ON u.id=o.userId GROUP BY c.name;