I'm running a query and seems to be having a problem

I'm using source{d} CE and I'm trying to see the unique collaborators for a specific repo.

I'm querying the "commits" table, and my query is:

SELECT COUNT(DISTINCT commit_author_name), repository_id
FROM commits
WHERE repository_id = 'data-intelligence'
GROUP BY repository_id

and I get the number 57.

However, when I run the query:

SELECT DISTINCT commit_author_name, repository_id
FROM commits
WHERE repository_id = 'data-intelligence'

I get the distinct names of
Marcelo Novaes
Fernanda Gomes
Máximo Cuadros

So, the unique number of collaborators is 3 but I get 57 if I do COUNT(DISTINCT commit_author_name).
I don't understand why.

The version of source{d} CE I'm using is v0.14.0-beta.3