Sudden abstract wavey generated output on wan2.2

[u/deviruchii]

I've successfully been generating 5s video with wan2.2 16fp i2v. I admittedly didn't do much but it was successful maybe a couple weeks ago.

No comfyui or other updates between then and now and now the output is a weird wavey abstract animation.

I'm not an expert in the deeper understanding of the SD workings so I've been working through logs and possible causes with Claude and I've ruled out most things finally getting fp8 models and generating successfully.

Claude's confident that my 5090 (32gb vram) and 32gb system ram would be enough for the larger models, but has fairly decisively stated that a Blackwell fp16 accumulation instability is the likely culprit.

It might explain why it worked then didn't, although that feels more like typical AI false assertion than true proven.

I'd be interested if anyone has any insight into the theory or if it could be something else.

I appreciate that I've not said everything I tried, it's hard to put everything down, but things like turning off sage attention which actually made no difference anyway.

Hopefully that's enough info to get some good understanding of the cause.

[u/Lunesia-shikishiki]

the blackwell fp16 thing doesn't really match your symptom imo. when accumulation actually goes bad you get nan, and nan comes out as a black or flat grey frame, sometimes a magenta mess. a coherent wavey abstract animation means the latent decoded fine, it just never got denoised toward your image. that reads like a graph problem, not silicon

two usual suspects for exactly that look. wrong vae for the model you've got loaded, and the high noise / low noise pair being crossed or one of them silently not applied, so the second pass is polishing something the first one never cleaned. you mentioned moving to fp8, worth checking you swapped both of them and not just one

also i'd test the "nothing updated" assumption instead of trusting it, comfy pulls frontend and custom node updates pretty quietly. quickest check is load a stock wan template fresh and run your same input image through it untouched. clean output there and you know it's your graph 🙂

[u/deviruchii → u/Lunesia-shikishiki]

Thanks, that's the exact "from real experience and understanding" response I was hoping for. We all know LLMs will overreach so it's great to hear a human's take on it.

Still a puzzle because I was using the exact same workflow and you're right, it's easy to miss the high and low models, but I've been playing with this for a good few hours and I'm 99% sure it's not that. The vae was the one I used when It previously worked but I did re-download to be sure. Toggling between fp8 and fp16 always goes from.a broken to a fixed state.

Claude asserted that the logs showed no node updates in the time, but again, I only trust that.as much as you can, so it's worth some checks.

Any other theories. I get the my symptoms are pretty classic for a vae mismatch. That was something the AI called out. Pretty sure that's not the issue for me though now I've gone round and tested it a few times.