i'm also having an issue where a lot of the time i cant mix coal and iron to get steel, it works some times but a lot of the time it only wants to make a coal ingot and then the ingot of coal looks like it'll be made but it never is
Coal ingot and Zinc Ingot do not exist, thus of course it'd never be made, though, It's really not supposed to show coal ingots at all.
As for steel alloy - if there's ever an issue with it not displaying, try removing the ore and putting it back in, and/or moving the smelter, as the detector might have gotten blocked by something (unlikely)
If those don't work, go for a save reload rather than trying anything else, but first, remove the ore that you can, then do the reload.