Project brogram (Hobby plan) has stopped creating fresh production deployments from new commits. I've tested every trigger mechanism and all of them fail the same way — instead of building the current main HEAD, Vercel silently reuses/copies an old already-built deployment (action: "redeploy").

What I've tried, in order, over the past day:

1. Full Git integration disconnect/reconnect (Project Settings → Git) — no change in behavior.
2. Confirmed via git ls-remote origin main that GitHub's HEAD is correct — not a local/stale git issue.
3. Ruled out: DB migration drift, Vercel plan build-minute limits, vercel.json git/github config, Ignored Build Step (set to Automatic), commit author email mismatch, branch protection rules, GitHub webhooks (repo's classic Webhooks page is empty as expected — Vercel uses the GitHub App, not a classic webhook), deploy keys, GitHub App repo access (set to explicitly include this repo).
4. Found and fixed "Auto-assign Custom Production Domains" was disabled under Environments → Production — re-enabled it. Did not fix the core issue.
5. Deleted the stuck deployment (dpl_6V7iD5HuXiiJyKVykkrBScQTGrdu) and its two redeploy copies via the dashboard, since every trigger kept copying it instead of building fresh. This also wiped the project's custom domain assignments (brogram.app/dentalist.app went down — domains: [ ] via API).
6. Pushed a fresh empty commit — zero new deployments created (verified via GET /v6/deployments).
7. Called the project's Deploy Hook directly via API (POST /v1/integrations/deploy/{projectId}/{hookId}). Got 201 with {"job":{"state":"PENDING"}} — but no deployment ever materialized.
8. Manually clicked "Redeploy" in the dashboard as a stopgap. This restored the custom domains, but the resulting deployment was — again — "action": "redeploy" with "originalDeploymentId" pointing at a deployment from 2026-08-11 (dpl_BuMoxoQZen1Es39yA22XrQkyiGEq), not a build of current main. Site is live again but running ~1 day stale code.
9. Pushed one more empty commit after that — again, zero new deployments.

Summary: three independent trigger mechanisms (git push, Deploy Hook API, manual dashboard Redeploy) all fail to produce a fresh build. The only "successful" deployments are copies of old, already-built ones. This looks like a stuck deployment-creation queue/pointer on Vercel's backend for this specific project, not anything fixable from the client side.

Has anyone seen this before, or can a Vercel team member take a look at project prj_cu5URJF0v9aGuXvHE7jgcBzVnfKz?