I tried out this mod yesterday and experienced the disappearing item issue in the Ammo crafting bench. Like others have mentioned, remaining nearby the bench while it is crafting the items will automatically drop into inventory. Moving a distance away this will stop and returning to the bench the items are no longer on the bench.
This actually may be an issue with the SMX UI @ViperInfinity. If you start crafting things and move away from the bench, then return to the bench the items are still there but aren't showing in the UI... I discovered this by accident by picking up the ammo bench to move it, and acquiring all the items that were crafted and sitting in it that I couldn't see. HTH
For others like @Praetor and @Bass_junke give picking up the bench (annoying to pick it up and replace it again for sure) to see if you get your disappearing items.
