You said Smiths as in plural, multiple Smiths. There can be only 1 Smith for that ore in the empire now.
That would be a bug in design then. Is this because the Smiths now have a vicinity access requirement for Ingots? They are not supposed to. It's supposed to be a normal prerequisite, not vicinity.
It MIGHT have been changed to try to help the AI not build one everywhere because like factories, they come with unhealth that the AI doesn't consider when it sees the added benefits only.
EDIT: However there's also good reason why it shouldn't be vicinity prerequisite for ingots. If it is, it means you cannot trade for ingots to get Smiths, and Ingots were historically made for ease of trade to local production sources everywhere they could be distributed.
EDIT 2: Based on history and the generic nature of the term 'wares', I would almost prefer Ware requirements to be vicinity based rather than the ingots. Particularly up to the industrial era at least, and then those would be further transmitted to more specific products in local buildings, then those products could be traded and sent about. But that end of design is not necessary right yet imo. What IS necessary is getting Smiths to take ingots as a normal prereq rather than vicinity.
EDIT 3:
So what happens when you have 2 sources of the same ore? The 2nd source is useless now? Can't build a smelter in that city even though it has the resource cause another city already built it's smelter. Hmmm.....wasted resources...…"not bad design really"......really?
When you have 2 sources you can build a smelter wherever those sources exist. If you have 2 sources in the same city then you obviously can't build 2 smelters but you can also build 2 smelters if you overlap vicinity of 2 different cities on one source. Only the National Smelter is limited to one per nation. The minor ones can be built in any city that has vicinity access to ore.
You can construct the one National Smelter you get in a city that doesn't have vicinity access at all. DH is trying to insist that it be required to
only build that where vicinity access doesn't exist. Again, I don't agree with this and feel it should somehow just give faster construction to units and buildings that require the metal it's smelting as well as giving Ingots to everywhere.