Conditional Access (CA) policies in Microsoft Entra ID might be the issue! Policies like "block unmanaged devices" or "blocking non-domain-joined devices" can block CSP logins, even with B2B guest exclusions, as CSPs are flagged as "Service provider users."
♟️ Impacts
♦️ Can’t access Microsoft 365 Admin Center.
♦️ Unable to manage subscriptions, assign licenses, or create Severity A or B support tickets.
♟️ What You Can Do
♦️ Ask customers to exclude "Service provider users" in CA policies (Entra ID > Protection > Conditional Access > Users > Exclude).
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