Most likely a runtime version mismatch. An update only goes to builds with the same runtimeVersion. If your build has "runtimeVersion": { "policy": "appVersion" } and you bumped version in app.json after building, the update targets a runtime no build has.
Check on expo.dev → Updates: the update shows its runtime version; compare with the build's. Also note the default behaviour: the app downloads the update on launch and applies it on the next launch, so it takes two cold starts.