To rule out anything stuck on the original App ID, I created a completely new Bundle ID (br.com.minhapecuaria.ios2) from scratch:
New App ID registered in the portal, Sign In with Apple capability enabled. New App Store provisioning profile generated and installed, tied to that Bundle ID. New app record created in App Store Connect for it. Manual signing in Xcode, explicitly selecting the new Distribution certificate + new profile. Verified via codesign/security cms -D: Apple Distribution identity, get-task-allow: false, no device list — a genuine App Store signature. Uploaded via Xcode Organizer → same result: error 90034 ("Missing or invalid signature... not signed using an Apple submission certificate").
Since this Bundle ID never existed before, there was nothing "stuck" on it — no stale provisioning history, no cached signing decision tied to that specific App ID. The fact that the error persists identically rules out anything project-specific and points squarely at the account/Team level (Team ID 395DDXTXHC).
I've also opened a support case (20000125779862) with this exact evidence, but so far only received generic first-line responses (certificate basics, Feedback Assistant suggestions) that don't address the account-level nature of the issue. Posting here in case anyone has seen this specific pattern — same 90034 across two independent Bundle IDs/certs/profiles under the same Team.