Regarding different outputs for the same seed: have You changed seed source to CPU in A1111? The noise You get that way is consistent across different hardware vendors and different from the GPU-sourced one.
I have used A1111 just now to check and got very simmilar results to ComfyUI that way.
Pretty much vanilla, only --xformers --medvram arguments and CPU seed. In that case, someone with more A1111 experience should weigh in, mine is limited, I mainly use comfy nowadays and probably am not up-to-date with development.