Link: https://huggingface.co/Lightricks/LTX-2.3/discussions/13

Note I found one comment which works for me in there: https://huggingface.co/Lightricks/LTX-2.3/discussions/13#69b26bb65d8741ba168540b4

Use 0.987, 0.85, 0.725, 0.422, 0.0 in your upscaler sigmas. This seems to work for me, but ofc it adds one more step than before, so the speed is reduced. This works well if you're planning to re-use the last frame of the video to extend it or smt.

Another solution that works is to simply cut off the lat 18 frames from the video and make it 18 frames longer. Υou can just extract the last frame at the point of cutoff. What I do to avoid cutting off speech (if there is one), I might add "there's a moment of silence" in the end of my prompt. Then the cutoff frames don't interrupt anything