LG Smart TV App Shows Device Offline — Fix ThinQ, Same SSID & Local Network Issues

Hi! When an LG Smart TV app shows the device offline, the tricky part is that the TV can look “fine” (Netflix/YouTube still stream) while the app can’t reach it for remote features (power on/off, volume, inputs, ThinQ dashboard).

I’ll keep this to safe diagnostic checks — no factory reset, no “guaranteed fix,” and nothing that risks your accounts.

First, which app are you using: LG ThinQ, the older LG TV Plus / LG Smart TV app, or a third-party app like Google Home? And what’s the main symptom — does the TV show “offline” in the app, or does the app not see the TV at all?

That’s a classic pattern: streaming works but the control path from the phone to the TV fails. That usually points to one of these “layers,” and we can test them safely:

Layer A (same network): phone and TV must be on the same Wi-Fi network (and sometimes the same band), not one on cellular or guest Wi-Fi.
Layer B (router rules): some routers block devices from talking to each other (AP isolation / “client isolation,” guest network separation).
Layer C (app/account): ThinQ signed into the wrong account, stale pairing token, or the app lost local network permission.

Quick questions (answer in any order):
1) Is your phone currently on Wi-Fi or mobile data?
2) Do you have more than one network name at home (like “HomeWiFi” and “HomeWiFi-5G”)?
3) Did this start after a router change, ISP swap, TV update, or phone update?

New router is a big clue. With many ISP routers, the TV can reach the internet (so apps stream), but the phone can’t “see” it locally for ThinQ control.

Let’s do the lowest-risk checks first, in a calm order:

Check 1: Force the phone to stay on Wi-Fi for 2 minutes.
Temporarily turn off mobile data (or enable airplane mode, then turn Wi-Fi back on). If the LG ThinQ device offline message changes to online even briefly, we’ve confirmed it’s a network-path issue and not “TV is broken.”

Check 2: Confirm the exact Wi-Fi name on BOTH devices.
On the TV: Settings → Network → Wi-Fi (or Network Status). On the phone: Wi-Fi details. Are they on the same SSID (same name), or is the TV on “HomeWiFi” while the phone is on “HomeWiFi-5G” (or guest)?

If you tell me the two network names you see, I can help you pick the best one for stability without changing anything major.

Good test — now we know it’s not “phone was on cellular.” If both are on the same SSID and it still says offline, the next likely cause is router separation rules (very common on ISP gear) or a permission/token issue in the app.

Two safe questions that narrow it down fast:

1) Can any other phone in the house control the TV in ThinQ?
If one phone works and yours doesn’t, it’s usually app permissions or account state on the phone.

2) Does the TV show as “connected” in its Network Status test?
Some LG TVs will show a Network Status screen with icons (TV → router → internet). If TV→router is OK but local control still fails, it points to isolation settings or the TV being on a segmented/guest network.

Also: when you open ThinQ, does it ask for Local Network permission (iPhone), or does Android show any permission prompts like “Nearby devices” or “Local network”?

Yes — iOS updates can affect whether an app can discover devices on your local network. If both phones show “offline,” it could still be router isolation, but it’s worth checking permissions because it’s quick and harmless.

Safe check (iPhone): Settings → Privacy & Security → Local Network → make sure LG ThinQ is allowed. If it’s off, the app can behave like “LG TV shows offline in app” even when Wi-Fi is fine.

Next, a router-related check that doesn’t require admin knowledge:
Try connecting both phone and TV to the same band for a test.
Some routers steer devices between 2.4 GHz and 5 GHz. For discovery/control, keeping both on one SSID can help temporarily. If your router has separate SSIDs (which yours does), try the TV on “HomeNet-5G” just for a test, or the phone on “HomeNet” consistently for 5 minutes — we’re only observing whether the TV flips to online in ThinQ.

One more question: is “HomeNet” a regular network or a guest Wi-Fi? Guest networks often block device-to-device communication by design.

Great catch — that permission needed to be on either way. If it’s still offline after enabling it, we’ll keep moving through the safest checks.

Next, I like to distinguish two different “offline” meanings:

Offline type 1 (app cache / stale session): ThinQ is signed in, but the TV’s token is stale after a router change.
Offline type 2 (local discovery blocked): the router allows internet but blocks device-to-device traffic (often called “client isolation” or similar).

Here are two non-destructive tests:

Test A: Power cycle the TV the “real” way.
Turn the TV off, then unplug it for ~30 seconds (this clears some network modules more fully than standby). Plug back in and let it fully boot, then open ThinQ again.

Test B: Check the TV’s IP address, then see if it changes.
On the TV’s network info screen, note the IP (something like 192.168.x.x). If the router is handing out unstable leases, the control link can get confused. We’re not changing settings — just observing whether it keeps changing a lot.

While you’re there, does the TV show it’s connected via Wi-Fi (not Ethernet), and is signal strength decent?

Understood — and it’s helpful that this is a modern webOS TV. At this point, since both phones behave the same, I’d lean toward a router/device-to-device communication block OR the TV no longer being properly linked in ThinQ after the router swap.

A few safe observations that often reveal it without diving into advanced menus:

1) Does the TV show up as “online” anywhere else?
For example, if you use Apple AirPlay, does the TV appear in the AirPlay list when both are on the same Wi-Fi? If AirPlay works but ThinQ shows offline, it’s more app/account than network isolation.

2) Does ThinQ show the TV as offline immediately, or does it spin/try to connect first?
Immediate offline often means it can’t discover/reach the TV locally. “Trying to connect…” then failing can be token/account state.

3) Any VPN, Private Relay, or security app on the phones?
Even some “privacy” settings can interfere with local discovery. We’re not changing security permanently — just checking if something is actively blocking discovery right now.

That’s a really useful clue: if AirPlay works, your basic local network path is probably OK. The “offline immediately” behavior in ThinQ after a router swap often comes down to the TV being linked to the old network identity (even if the SSID name is the same) or the app holding onto a stale pairing state.

I’ll stay within “safe checks” and avoid anything drastic. Here’s a careful sequence that helps diagnose which side is failing — phone/app vs TV link — without jumping straight to resets:

1) Confirm ThinQ is signed into the correct LG account.
If you have more than one email (or you previously used a different login), the TV can appear but never come online.

2) Refresh the app session (lightweight).
Fully close ThinQ (swipe it away), reopen it, and pull to refresh the device list. If the TV briefly “wakes” then drops offline, it usually indicates a handshake problem rather than Wi-Fi strength.

3) Check if the TV has any pending software updates.
Not to “fix everything,” but because app-to-TV integrations can break when one side updates and the other doesn’t. Just check availability — you don’t have to update right this minute.

4) Look for any “Mobile TV On / Wake on Wi-Fi / Quick Start” style setting.
Different LG models label it differently. If that feature is off, the TV can stream fine when on, but app control (especially power-on) can fail. Don’t change a bunch of toggles — just tell me what you see in that area.

If you can paste the exact wording of the offline message and the TV model series (like OLED C2/C3, UQ, QNED, etc.), I can help you interpret which layer is most likely without guessing.