Multi-factor authentication and StaffHub
StaffHub and Azure Active Directory conditional access
If you have any global or conditional access rules enforced which include SharePoint Online for your Office 365 tenant, even if you explicitly exclude StaffHub app from in the conditional access rule, this doesn't exempt enforcement of the rule for StaffHub in your Office 365 subscription. For example, if you have MFA enforced, your users will still be prompted for a second form of authentication when they sign in to StaffHub. This is because StaffHub has an internal dependency on SharePoint Online, and will be excluded from MFA only if you also exclude SharePoint Online by using conditional access rules.