I presume this should compact into ingots with the steel tag? Currently just voids the molten steel.
dotCatshark commented
Also, bronze has the same issue.
rbasamoyai commented
The recipe viewer you're using probably does not have a case for when a tag is missing (JEI does.) Install IngotCraft (or any other valid tagged mod) if you want access to steel and bronze. This is planned to change in a future update.