Mapbox Studio style rollback after a failed upgrade: what actually carries over to clients?

Answer

After you roll back a style in Mapbox Studio, already‑running map instances (Mapbox GL JS, Android SDK, iOS SDK) continue to display the style that was loaded when the map was created. They do not automatically pick up the reverted version until they request a fresh style load.

Confirmed facts

1. Rolling back restores the previous published style JSON (sources, tilesets, layout, paint) but does not push an update to client‑side caches.
2. The rollback operation creates a new version entry that becomes the current published version; the Styles API GET /styles/{style_id} returns the restored JSON, and GET /styles/{style_id}/versions shows the new version as the latest with identical content to the restored style.
3. Styles that were last edited before the 2020 versioning overhaul must be migrated to the Mapbox GL Style Specification v8 before the rollback UI is available. Opening the style in Studio triggers a migration prompt; after publishing the migrated version, rollback works normally.

Likely explanation

Mapbox GL JS and the mobile SDKs load the style once at map initialization and keep it in memory. Subsequent tile requests reference the already‑loaded style JSON, so a server‑side change (including a rollback) does not propagate unless the client explicitly asks for the style again.

Steps to make running clients load the reverted style

1. Mapbox GL JS: call map.setStyle(styleURL) again, or append a cache‑busting query string (e.g., styleURL + '?v=' + Date.now()) to force a fresh fetch.
2. Android SDK: invoke mapView.getMapAsync { map -> map.setStyle(styleURL) } or recreate the MapView with the same style URL.
3. iOS SDK: call mapView.styleURL = styleURL or mapView.setStyleURL(styleURL) to trigger a reload.

Verifying the rolled‑back style via the Styles API

1. Obtain your style ID and a valid access token.
2. Request GET https://api.mapbox.com/styles/v1/{username}/{style_id}?access_token=YOUR_TOKEN before and after the rollback; the returned JSON should match the pre‑upgrade style.
3. Optionally list versions with GET https://api.mapbox.com/styles/v1/{username}/{style_id}/versions?access_token=YOUR_TOKEN and confirm that the newest version number has incremented and its created timestamp corresponds to the rollback time.

Missing diagnostic detail (only needed if it changes the recommendation)

If you are using offline packs or pre‑cached tile bundles, a simple style reload may not update the displayed tiles; you would need to clear or regenerate those offline packs. Let me know whether you rely on offline data so I can advise on the additional step.