Basically, the content in Studio One according to the User License is yours to use however you like, without credit given. But depending on your use of the songs you are producing, it is sometimes frowned upon in the music industry-community to use stock samples "as is" without any modification. You have to keep in mind, there are a lot of other Studio One users with access to the same samples, so when you find some you like, tweak them out a bit to make them more unique and "yours".
We also encourage you to create a thread about this on the Presonus user forum. https://forums.presonus.com/viewforum.php?f=108
This will allow for back and forth discussions about an issue or question and more points of view as to possible different approaches or workflows.