Your issues may be related to those I experienced with an iMac and the latest Studio One 3.
As I anticipated my Mac problems have been resolved by Presonus support informing me that they have moved the Studio One content downloads to a higher priority location yesterday.
That declared action must have been implemented because I am now able to obtain all the 36GB of Studio One 3 content for my iMac.
For detail of my issues see the Studio One 3 section of this forum:
Are content download problems for Mac’s recognised and what active steps are being taken to eradicate it ?