Issues with black or non-denoised generation with Flux
I run ComfyUI Portable on my laptop to generate images with Flux. I have been doing it for months with no particular issues but then suddenly (but without any specific update or custom node installation to pin it to) I have had issues with images being just black or not denoised at all.
It seems to happen randomly, it may happen with any workflow (basic generation, with or without LoRA, ControlNet, Img2Img etc - no pattern). If I load a workflow by dropping a previously generated image on the canvas, it might give me a black or non-denoised image one time, end then a perfect generation the next.
I've tried updating Comfy, I tried installing a new instance of Comfy (this helped for a while). I have tried "Cleanup of VRAM" and to look for conflicting custom nodes etcetera but still the issue persists - randomly (but at times more often than not).
I cant see anything out of the ordinary in the command prompt when this happens.
Any ideas on what could cause this or what to do about it would be greatly appreciated!
Odd thing... I can take one of the failed generated images, one that is just noise, drop it on the canvas and then generate a perfectly fine image from that. It is a complete lottery it seems!