I'll tell you my process for coming up with new stories, and maybe that can help you a bit.
My method for coming up with story concepts is I only write the things that consume me. I will not write a story unless it's something that intrusively forces it's way into my thoughts, and I find myself obsessively going over character development and concepts and all the ideas really excite me.
Maybe it will take some research or development to bring to fruition. But, the subjects I need to research need to actually just spring to mind, and cause me to want to just excitedly jump into the research or world-building topics with wild abandon.
That excitement is the best sign that you have something good going for you.
It does not always just work like that. Sometimes, you need to get it over a block of some sort before it just starts... flowing like that. I have a currently unreleased story I'm working on right now. It was inspired by Raven's Dagger's "The Agartha Loop." He just dropped the story after the 2nd loop, and I felt disappointed. I wanted to tell my own version of a magical girl time-loop story that inspired all the same feelings Agartha Loop triggered in me, and managed to continue the story.
But, the thing is, I couldn't just write the same story as Raven's Dagger. That would be uninspired plajerism. So, I had to come up with my own take on the concept. But, I found myself bashing my head against the wall as I was trying to develop a concept.
What finally wound up working is I decided to flip my way of looking at it on it's head. I wanted to write an Agartha Loop inspired magical girl series because I loved Agartha Loop. But, in order to come up with my own take on the story, I had to look at it and figure out every single thing that I thought was bad about the story. Everything I hated, and every fatal flaw in the story that I felt should be improved upon.
I started coming up with answers startlingly quickly for a series that I'd loved up until that point, and all of a sudden I started seeing flaws everywhere. And, for every flaw, I also saw something that could be altered, changed, and improved upon.
After that, the ideas started flowing, and I had so many ideas coming so fast.
I am now writing about a chapter a day, around 3,000 words per chapter, and have plans to pre-write an entire 40 chapters ahead making sure all of them are very well edited and considered before I drop the first 10 for public release. (Just started chapter 29.)
That was my experience. Maybe there was something in there that could help you, maybe it's all useless to you. But, just giving you my experiences is the best I have here. If there's something in that you can use, then that's fantastic.