Why might user A not see user B's Calendar?

User A might not see User B's calendar because User B's calendar is not shared as Public. In NetSuite, calendars can be configured with specific visibility settings. If User B has not shared their calendar publicly or has set it to a private status, then User A will not have access to view it. Sharing settings play a crucial role in controlling who can see a user's calendar, making this option the correct reason for why User A can't see User B's calendar.

In contrast, while restricted roles or different Centers can affect access, they are not the primary cause in this context; they generally pertain to overall permissions rather than specific calendar visibility. Also, clearing a browser cache usually addresses issues with content not loading properly, which would not effectively restrict calendar visibility based on user roles or sharing settings.