Admin API not fetching Clusters by Project

Hi! I noted a strange behavior with Atlas API.
If I call I get the clusters for all my groups (only one in my case). I also get the group ID.
If I then call{group_id}/clusters with the group obtained on the previous call, I get an empty array as response.

I checked permissions, parameters, and more, and everything seems to be correct.
I’m using postman for these tests.

Anyone ran into something similar? Is it a bug?