This confusion is more common than you might expect and there is a straightforward explanation for most of it.
Leavenworth is actually home to two distinct federal facilities that share the same general location and often get conflated in databases and search results. There is the United States Penitentiary Leavenworth, which is a high security federal prison, and there is the Leavenworth Federal Satellite Camp, which is a minimum security facility that sits adjacent to it. They are separate institutions with separate populations, but because they share a geographic location and similar names, records and locator tools sometimes display them interchangeably or incorrectly.
A 37 month sentence at a satellite camp is consistent with a lower security classification, typically for nonviolent offenders. That placement makes sense given the sentence length and the camp designation. The penitentiary next door houses a very different population under very different conditions.
On the contact issue, newly arrived inmates at federal facilities go through an intake and orientation period before phone and visitation privileges are fully activated. That process typically takes about a week from arrival. During that window he may not have access to the phone system or be able to add numbers to his approved call list yet.
The most reliable way to confirm his exact location and current status is the Bureau of Prisons inmate locator at bop.gov. Search by his name or federal register number and it will show you which facility he is officially assigned to. If the locator shows the penitentiary rather than the camp, it may simply be a database display issue that reflects the broader Leavenworth complex rather than the specific unit.
Give it another week and try reaching out through the BOP locator and by sending a letter to the camp address directly.