Rest API call https://<pam server>/api.php/v1/users.json returns 10 users only, even though we have over 1500 users defined in PAM.
Any PAM release as of April 2022.
The default limit for this API call, and many others, is 10, see the details on this call in the Settings > Api Doc page.
Add parameter limit=0 to the URL, like https://<pam server>/api.php/v1/users.json?limit=0