[Bug] LTX 2.3 Produces garbled videos on R9700/w Vulkan

[celer]

Git commit

c6beeef

Operating System & Version

Arch Linux / CachyOS 7.1.6-1-cachyos

GGML backends

Vulkan

Command-line arguments used

build/bin/sd-cli -M vid_gen --diffusion-model ~/models/checkpoints/ltx-2.3-22b-dev-UD-Q4_K_M.gguf --vae ~/models/vae/ltx-2.3-22b-dev_video_vae.safetensors --llm ~/models/text_encoders/gemma-3-12b-it-qat-UD-Q4_K_XL.gguf --embeddings-connectors ~/models/text_encoders/ltx-2.3-22b-dev_embeddings_connectors.safetensors -p "a lovely cat" --cfg-scale 6.0 --sampling-method euler -v -n "worst quality, low quality, blurry, distorted, artifacts" -W 1280 -H 720 --diffusion-fa --offload-to-cpu --video-frames 33 --fps 24 -o t2v.webm

Steps to reproduce

1. Acquire all the specified models in the LTX2.3 readme (btw the write up links to the non QAT unsloth gemma, I've tried both)
2. Copy the first T2V command from the LTX2.3 readme, update it to point the correct model locations
3. Run it

What you expected to happen

I expected it to generate a video which matched the prompt

What actually happened

I got a garbled output that looks like this:

Logs / error messages / stack trace

sums.txt

log.txt

Additional context / environment details

CPU: AMD Ryzen 9 9900X (24) @ 5.66 GHz
GPU 1: AMD Radeon AI PRO R9700 [Discrete]
GPU 2: AMD Radeon AI PRO R9700 [Discrete]
GPU 3: AMD Radeon Graphics [Integrated]
Memory: 6.05 GiB / 60.40 GiB (10%)

[celer]

rocminfo.txt

vulkaninfo.txt

[celer]

hmm, this is a regression from master-813-bfbef5b as it works fine in that release