SQL - Why does the GROUP BY clause cause a difference in my result?

Question

I'm learning SQL on Datacamp and I run into this question:

In how many different years were more than 200 movies released?

The answer to it is 13.

Here is my solution which produces the wrong answer: 91

SELECT count(distinct release_year)
FROM films
HAVING count(title) > 200;

I got the right answer when I changed a code a bit as below:

SELECT count(distinct release_year)
FROM films
GROUP BY release_year
HAVING count(title) > 200;

Could anyone please help explain why adding the GROUP BY clause can cause this change. I learn that GROUP BY helps group the results and only affects how the result table displays.

Thank you so much.