Clay Forge in Neitzinot cannot be used to smelt Molten glass
What I did: tried to make Molten glass at the forge in Neitiznot
What I expected to happen: to be able to smelt it
What actually happened: nothing
IDs of related NPCs/items: Bucket of sand 1783, Soda ash 1781, Molten glass 1775
2009-era source (if relevant): https://runescape.wiki/w/Clay_furnace?oldid=1650960
Screenshots or video: