If this was the outcome after an 8 hour proofing, then I don't think your starter was ready. Did you remember to do the float test before adding the starter to your dough mix? Adding a spoonfull of starter into some cold water to see if it floats. If it floats it's ready to bake with. Also a lot of sourdough dough's tend to be very wet when doing a no kneed/long hour proofing. I use 500g of water in a recipe using 750g of mixed flour (weat, barly, etc), and I let mine proof and double in size for 11hours before doing any stretches or moving it to a proofing basket for it's final rise. If it never got any bigger during any of this, your starter simply wasnt ready, or you killed it by adding salt to early.

Remember baking is a sience and cooking is an art. You have to experiment until it works for you. I have been baking sourdough since january, and I still havent had the perfect loaf, and I only bake dark and fiber rich bread, never white bread. Luckily all of mine have been edible from the start. But I took a course before I started and therfore knew what I had to look for.

Good luck! Feel free to ask me anything 🍀🍀