Ran into the same thing and had Claude fix it. Short version as I understand it is that I had just upgraded my dev account from free to paid, and it didn't rebuild the WidgetKit extension under the new paid profile. Details from Claude: I diagnosed this for a user whose app showed these exact symptoms — black Dynamic Island container (tapping it opened the app, so the activity existed), empty expanded view, and no Lock Screen presentation, with the widget extension's SwiftUI content never rendering. Clean builds, a DerivedData wipe, reinstalls, and a device reboot all failed to fix it. The cause was a stale cached provisioning profile from a free-team era. The user had upgraded their personal Apple Developer membership from free to paid, which keeps the same Team ID — so Xcode's automatic signing saw no reason to regenerate cached profiles. Four of the app's targets carry entitlements (Family Controls, App Groups) whose provisioning needs changed with the upgrade, forcing fresh paid profiles; the WidgetKit extension needs no special entitlements, so Xcode silently reused its cached 7-day free-team profile from before the upgrade. Same team ID, technically valid signature — but the Live Activity would not render. I found it by comparing the embedded profiles across the built app and all of its appexes: for P in Build/Products/Debug-iphoneos/YourApp.app{,/PlugIns/*.appex}; do echo "$P"; security cms -D -i "$P/embedded.mobileprovision" | grep -A1 -E "CreationDate|ExpirationDate" done Four profiles showed ~1-year validity (fresh, paid); the widget extension's showed a ~7-day window created days earlier — the tell. The fix: delete the stale profile from ~/Library/Developer/Xcode/UserData/Provisioning Profiles/ (identify it by security cms -D -i | grep application-identifier), rebuild so Xcode mints a fresh profile, then delete the app from the device and reinstall. The Live Activity rendered immediately. (The same build also adopted .containerBackground(for: .widget) — recommended on iOS 17+ regardless — but the identical view code had rendered fine before the regression, so the profile was the operative fix.) If you're hitting this: it's worth checking any time an app partially breaks after a free→paid upgrade or any team change that keeps the Team ID — Xcode only re-mints profiles for targets whose entitlement requirements changed, and quietly reuses stale cached profiles for the rest.