Hey! We’ll get your SmartThings Hub apps not loading issue sorted — whether it’s an endless spinner, blank device list, or “Something went wrong.” Before we change anything, I want to pinpoint if this is a SmartThings cloud / server problem, a Samsung Account sync issue, or a phone app cache / network problem.

Quick questions (so we don’t guess):
• Are you on Android or iPhone? Any recent SmartThings app update?
• What hub do you have: Aeotec Smart Home Hub, SmartThings Hub v2/v3, or SmartThings built into a Samsung TV/Appliance?
• What exactly “won’t load”: Rooms, Devices, Routines, Home Monitor, or the whole SmartThings app screen is blank?
• Does it fail on Wi‑Fi and cellular, or only on home Wi‑Fi?
• Hub LED status (if you can see it): solid green / blinking / solid red?

Once you answer those, we’ll start with the fast checks you should do first — status page, connectivity, cache, and account refresh — before anything like a hub reset.

That detail helps a lot: automations still run locally but the app UI won’t load. That often points to one of these:
• SmartThings cloud outage / degraded service (app can’t fetch device states, history, scenes).
• Samsung Account authentication hiccup (token expired; app can’t sync your Location).
• Corrupted SmartThings app cache (endless spinner / blank page / missing Rooms).
• Network-level blocks: VPN, Private DNS, router firewall/adblock, or captive Wi‑Fi portal.

What to check first (fast + safe):
1) Open the SmartThings Status page and see if there’s an incident affecting app, hub connectivity, or cloud services.
2) Switch your phone connection: try SmartThings on cellular data (turn Wi‑Fi off), then try again on Wi‑Fi. If it works on cellular but not Wi‑Fi, we focus on router/DNS. If it fails on both, we focus on account/app or cloud outage.
3) Disable anything that can intercept traffic: VPN, ad-block DNS, Private DNS, or “Secure Wi‑Fi.”

Do those 3 checks and tell me what changes (even small differences like “loads slower” or “shows devices but not routines”).

Perfect — failing on both Wi‑Fi and cellular means it’s less likely a router-only issue. Let’s do the best “first fixes” in the right order so you don’t accidentally break your SmartThings setup.

Step 1 — Check SmartThings platform status
• If SmartThings is having an incident, the app can hang on loading or show “Something went wrong” even when your hub is okay.
• If you see an outage, the fastest move is to wait it out (we can still confirm your hub is healthy locally).

Step 2 — Temporarily disable Private DNS on Android
Some Private DNS providers block or slow the SmartThings endpoints, which looks exactly like “app stuck loading.”
1) Android Settings → Network & internet → Private DNS
2) Set to Off (temporarily) and relaunch SmartThings.

Step 3 — Clear SmartThings app cache (NOT data yet)
Clearing cache is safe and often fixes the spinner/blank screen.
1) Settings → Apps → SmartThings → Storage
2) Tap Clear cache
3) Force stop SmartThings, then open it again.

If it still won’t load after those three, we’ll refresh your Samsung Account session (sign out/in) and then check hub connectivity next.

That “hub appears then disappears” pattern is a strong clue for sync/auth issues or an app-side problem (rather than the hub truly going offline). Next checks are still safe and reversible.

Step 4 — Update SmartThings + system components
• Update the SmartThings app from the Play Store.
• On Android, outdated system components can break logins/loading. If you can, update Google Play system and ensure Play Services are current.

Step 5 — Refresh your Samsung Account session
If your token is stale, SmartThings can “half load” (UI opens, but devices/Rooms never populate). Try this sequence:
1) SmartThings → Menu → Settings → Sign out (if available) OR Android Settings → Accounts → Samsung account → remove/re-add (only if you know your password).
2) Reopen SmartThings and sign in again.
3) When prompted, allow permissions the app needs (network, nearby devices/Bluetooth if you use Matter/Thread onboarding).

Important: avoid “Clear data” unless we have to — that can make you re-download configs and re-link some services.

After you sign back in, tell me if the Rooms/Devices load but the hub still shows offline, or if it’s still stuck on loading.

Great progress: Rooms loading means the app/account is mostly healthy. Now we’re looking at a common split problem:
• Your hub can still run local automations, but the app shows hub offline or device tiles show “No response.” That can happen when the hub can’t maintain a stable connection to the SmartThings cloud, or when the app can’t fetch cloud state/history.

Step 6 — Do a clean hub reconnect (power + network)
1) If your hub uses Ethernet: check the cable is firmly seated in hub and router/switch. If it’s plugged into a switch, try a direct port on the main router for testing.
2) Unplug hub power for 30 seconds, plug back in. Give it 3–5 minutes to fully come online.
3) Reboot the router (optional but helpful if DHCP/DNS got weird).

What we’re watching:
• Hub LED should settle to its normal “online” state (varies by model).
• In SmartThings, the hub should change from offline to online and stay there.

If it flips offline again after it briefly comes online, we’ll check DHCP/IP changes (reserve an IP), DNS resolution, and whether your router is blocking SmartThings endpoints.

That’s a big clue. SmartThings hubs are pretty sensitive to DNS resolution and stable addressing. When DNS changes, you can see “hub offline” in the app even though some local actions still work.

Step 7 — Quick DNS + DHCP checks (high success rate)
1) In your router, set DNS temporarily to a known reliable option (or revert to ISP DNS) and test. If you were using a “filtering” DNS, it might block SmartThings domains.
2) Create a DHCP reservation for the hub (bind its MAC address to a fixed IP). This prevents “IP hopping” that can break cloud sessions.
3) Make sure the hub is not on a guest network / isolated VLAN. If you use advanced router features: disable “AP/client isolation” for the hub’s port/network.
4) Confirm your router’s date/time is correct (bad time can break TLS certificates and look like “can’t connect to server”).

Step 8 — Re-test inside SmartThings
After applying DNS + DHCP reservation, reboot hub once more and watch if it stays online for 10–15 minutes.

If you tell me the router brand/model, I can point you exactly where DNS/DHCP reservation is located so it’s quick.

Awesome — hub staying online after DNS/DHCP is the major win. The remaining “Home Monitor spinning / slow history” is often one of these:
• Temporary SmartThings cloud performance issues (history + monitor pages are cloud-heavy).
• App rendering/cache quirks after a big update (especially on Android).

Step 9 — App-side performance checklist
• Force stop SmartThings and reopen it (fresh session).
• Make sure SmartThings has permission to use network in the background; if your phone has aggressive battery optimization, add SmartThings to “Never sleeping apps.”
• Keep Private DNS off for now (or switch to a non-filtering provider).
• If it’s only one screen (Home Monitor) that spins, try switching between Favorites/Devices/Automations once, then reopen Home Monitor — this sometimes forces a refresh of stale state.

When to reset the hub?
Only if the hub won’t stay online even after DNS/DHCP is stable, or if devices permanently show offline and won’t recover. A full hub reset is a last resort because it can mean re-adding devices. We’re not there based on what you described.

That’s super common and it’s almost always app/session-specific on the second device.

Fix when SmartThings loads on one phone but not another
1) On the partner’s phone: clear SmartThings cache and force stop.
2) Confirm they are signed into the same Samsung Account and they can see the correct Location (sometimes it opens into a different Location and looks “empty”).
3) Update SmartThings app to the same version as yours.
4) If it still shows blank devices: uninstall SmartThings, reboot the phone, then reinstall and sign in again.

If you want, tell me both phone models + Android/iOS versions — some versions are more prone to “endless loading” until permissions/battery settings are corrected.

Love it — that’s the exact pattern we like to see. Summary: when SmartThings Hub apps are not loading, check the SmartThings status page first, then rule out Private DNS/VPN, clear the app cache, refresh your Samsung Account session, and finally stabilize hub connectivity with solid DNS + a DHCP reservation (especially for Ethernet hubs). If you get stuck or see “hub offline” flipping back and forth, open the chat and we’ll troubleshoot your specific hub/router setup step by step.