webOS 26 (Firmware 43.21.71) - Live Stream (HLS/MPEG-TS) Playback Loop & Buffer Underrun Bug on C3 OLED

Device & Software Specs:

  • Model: LG OLED55C34LA.AEU (LG OLED evo 4K 55" C3)

  • OS Version: webOS 26 (webOS version 11.2.0)

  • Firmware: 43.21.71

Issue Description: Since updating to firmware 43.21.71, live stream playback on IPTV applications has become unusable due to an endless playback loop.

  • Behavior: The stream plays for approximately 2 to 3 seconds, stops, shows a loading spinner, jumps back 1–2 seconds in time, and replays the exact same frame sequence. This buffer underrun/looping cycle repeats indefinitely.

  • Formats Tested: Both raw MPEG-TS (.ts) streams and HLS (.m3u8) playlists exhibit the exact same bug.

  • Scope: Tested across three separate IPTV player applications built for webOS; all display identical failure modes, confirming the issue originates from the OS-level HTML5 Media Source Extensions (MSE) / AVPlay pipeline rather than application-specific logic.

Isolations & Troubleshooting Performed:

  • Network & ISP: Issue persists across fiber connections (Orange Livebox 6) and mobile Wi-Fi hotspots, ruling out ISP throttling, DNS issues, or router MTU limits. Custom DNS (1.1.1.1) and disabling IPv6 yielded no change.

  • External Cross-Check: The same live streams play flawlessly on PC/Mac using custom FFmpeg/VLC decoders.

  • Hardware Resets: Factory resets and power-cycle resets (disabling Quick Start+) do not resolve the issue.

Conclusion & Request: This points to a clear regression in the webOS 26 native media demuxer/decoder framework handling presentation timestamps (PTS/DTS) for live streams. Please log this regression for the engineering team to review in upcoming firmware patches.

1 Like

This forum only supports LG SDK and LG API related issues. For questions/issues about the use of LG devices, please contact LG customer service center in your region. Sorry for not being helpful.

It’s an issue with the firmware and the title and, underlying, purpose of this forum is the websotv. So, instead of being sorry, why don’t you redirect this post to whom can help? Tks!

I have been experiencing the same problem since September 18, 2026; what is the solution?