Liberating City States (maybe regular cities too, but I don't do that often) or puppeting cities leads to a weird production icon. The first pic shows the liberated CS and the production icon, while the second shows what happens if you click on it (sometimes nothing, but in the this case it brings up a puppeted city).
Lua file is attached.
This was happening in the last versions too.
Lua file is attached.
This was happening in the last versions too.