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.

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