Microsoft SNDS data display and delays are a multifaceted issue stemming from various sources. Common problems include data stopping unexpectedly (often around the 5th of the month), login errors resolved through workarounds like different browsers or incognito mode, and underlying causes like outdated infrastructure, Microsoft's broader infrastructure challenges, data processing pipelines, filtering and aggregation, and potential system issues. Authentication problems, insufficient sending volume, account permission issues, recent IP/domain changes, and discrepancies in IP reputation reporting also contribute. Microsoft documentation emphasizes processing times, non-real-time updates, and the importance of MSA association. Experts recommend checking authentication settings, verifying IP registration, escalating to support, and understanding the limitations of SNDS as merely an indication, not absolute truth.