If you turn auto generate off in the GenAI Config, you'll get a little menu over the image where you can manually trigger generation off new images, even if the code thinks nothing has changed and doesn't think a new image is needed, but if your progress is stuck at 0% I'd guess something has broken and needs a restart for it to work.
If there's something wrong with the "Only save background free images" the result would be like what you're describing, but I'm not sure how or why something would go wrong with that.
I guess if, for some reason, the order of the arguments to that script is different between our systems, it could cause issues. I haven't found any way to specifically say "this setting has this value" when calling the script, I only pass along a list of values based on the order of the settings like this:
true, false, false, "#000000", false
to say that the first check box of the settings should be checked (true) and the rest should be left unchecked (false).
But that leads us to the question, in the Automatic 1111 web-ui, when you select the script, is the "Only save background free images" setting the first shown? Like this:
View attachment 4948903
Or does it look different for you?