Summary: In Sandbox, Product.products(for:) returns all 3 of my IAPs with correct JPY prices and Japanese localizations, but product.purchase() fails immediately — the payment sheet is never presented — with ASDServerErrorDomain Code=3504 (Product.PurchaseError.productUnavailable). All 3 products fail identically. Reproduction captured in the sysdiagnose attached to FB24067333: 2026-07-30 18:43:58 JST — in-app purchase() on app.negaiboshi.placement; 18:44:40 JST — OS-level test (Settings > Developer > Sandbox Apple Account > Manage > Start Transaction), same product ID. Server correlation keys from the device log: inAppBuy → AMSServerCorrelationKey HNB5UGLE72AXSMY5KY7G4NAXQY (failureType 3504); Start Transaction → FQN4Y4JOEHYBW2GIR7KPTYTB2A (AMSServerErrorCode 3766, "provided product ID or bundle ID is invalid"). Environment App: Negaiboshi — Apple ID 6794682125, Bundle ID app.negaiboshi, Team 778QPP83C4 App status: first submission in preparation (never reviewed); build 1.0 (1) on TestFlight IAPs (all "Ready to Submit" since 2026-07-27 JST, attached to the 1.0 submission): app.negaiboshi.pro.monthly (auto-renewable, ¥480, group 22264517), app.negaiboshi.placement (non-consumable, ¥720), app.negaiboshi.nightsky (non-consumable, ¥1,200) IAP base country: Japan (JPY); availability 145/175 countries Device: iPhone, iOS 26.5.2; development build from Xcode; StoreKit Configuration = None Sandbox Apple Account: (address in FB24067333), region Japan, no purchase history; signed in under Settings > Developer Storefront.current = JPN. No Screen Time restrictions. Actual error (verbatim): Error Domain=ASDServerErrorDomain Code=3504 "このアイテムは見つかりませんでした。" UserInfo={AMSServerErrorCode=3504, client-environment-type=Sandbox, storefront-country-code=JPN} TN3186 checklist fully verified, none apply (Paid Apps Agreement, banking, tax all active; bundle ID + IAP capability; signing; membership). Also tried: Sandbox sign-out/sign-in, device restart — no change. Consistent across all 3 products and relaunches. Reproduced with zero app code involved (decisive): Settings > Developer > Start Transaction with product ID app.negaiboshi.placement and bundle ID app.negaiboshi fails: "The provided product ID or bundle ID is invalid. [Environment: Sandbox]" — Apple's own OS-level tool, no third-party code. Calibration: a deliberately nonexistent ID (app.negaiboshi.zzz) yields the identical error — the backend treats my real product like a nonexistent one. A price change (¥720→¥700, "now", 2026-07-29) propagated to the sandbox metadata catalog within minutes (products(for:) returned "¥700") — purchase() still 3504. Reverted. A full base-country change (2026-07-30): Japan (¥720) → United States ($4.99) at 15:52 JST — this deletes and recreates the price schedule and is the exact operation that resolved the identical symptom in thread 839557. It propagated to the metadata catalog (auto-converted ¥800 shown in ~20 min), yet purchase() and Start Transaction still failed at 16:10 and 16:55 JST. Reverted to ¥720 at 16:59 JST. Every lever that rewrites the price schedule reaches the metadata catalog but never the commerce/purchase catalog. Timeline: the products reached Ready to Submit hours after the 2026-07-26 15:22–17:58 PDT In-App Purchases outage (Message ID 1000005803), and the failure still reproduces after the 2026-07-29 16:20–19:30 PDT emergency maintenance on In-App Purchases + Advanced Commerce API (messageId 1000005805). Peer reports with the same metadata-vs-commerce-catalog split in the same window: threads 839220, 839441, 839437, 839645, 839557. Questions: Why does purchase() fail server-side with 3504 ("item not found") while products(for:) succeeds for the same IDs in the same JPN storefront? Can someone check the sandbox commerce-catalog state of the 3 product IDs above (Apple ID 6794682125)? This looks like a server-side provisioning failure that no developer-side action can repair. Is any additional App Store Connect state required before sandbox purchases can complete for a never-yet-reviewed app?