Hello, I found seemingly contradictory facts in r/askhistorians answers. This shows a transcript showcasing US military officials discussing how they could drop the next nuke within a fortnight and that monthly production would be 3-4. But I have seen restricteddata answer stating that US had no nukes at the end and very little capability to actually make more. So did US just scrap all nukes in production when Japan pulled up their hands? Or did I miss something?
So the 3-4 per month was assuming they were marching ahead at full capability on all fronts. It's basically an estimate of how much fissile material their plants were capable of producing at full capacity.
But once the war ended, they stopped producing it at full capacity. This was for a few reasons. One is that there was considerable uncertainty about the future of the nuclear program and the military was assuming (incorrectly, it turned out) that Congress would swiftly pass an Atomic Energy Act that would make it clear what the postwar situation was going to look like. But Congress rejected the War Department's bill and it took a year for them to create a new one, plunging the whole situation into limbo. In that limbo you had lots of people leaving their war jobs and going home, and needing to be replaced by new people, and that made the entire thing very chaotic. They still produced fissile material (especially at Oak Ridge), but they weren't assembling it into weapons at all.
They also had fissile material issues caused by their inexperience with reactors. At Hanford they anticipated a serious design flaw with their reactors (the Wigner Effect, which was causing the graphite to expand) and so they shut B Reactor down entirely so that if one of the other reactors failed they could restart it and have some capacity. So that reduced their production a bit.
But the main issue is that they just weren't turning the material they had into weapons cores, and weren't building the subassemblies for the weapons. This is because the system fell into disarray in the postwar. When the Atomic Energy Commission finally took over in January 1947, their first order of business was putting everything onto a stable peacetime footing, getting the capacity for weapons production up again, and — by the end of the 1940s — dramatically expanding the production of fissile material (through the building of new facilities like Savannah River, Portsmouth, and Paducah) and the facilities for routinely assembling bombs themselves (places like Pantex, as opposed to the "artisanal" bomb production of the Manhattan Project).
So there is really no contradiction — it is the difference between the wartime footing, and the relative chaos of the postwar situation.