Apple is still on shaky ground as its next earnings approaches.NurPhoto/NurPhoto via Getty ImagesTwo sets of analysts downgraded Apple, citing weak iPhone demand.Apple's AI-powered iPhone 16 has had mixed reviews; its biggest feature is unavailable in China.Chinese smartphone makers like Xiaomi are gaining market share over Apple in the key region.Wall Street's confidence in Apple's China performance seems to be slipping as its first-quarter fiscal year 2025 earnings announcement approaches.Apple, which is scheduled to report quarterly data on January 30, was downgraded to "underperform" by analysts at Jefferies.