[1.1.2589] "Smelt metal from slag" recipe always thinks there's 0 items in zone

[zed_0xff]

"Smelt metal from slag" recipe always thinks there's 0 items in a specific zone.

No mods at all.
When I set Electric smelter recipe to "Look everywhere" mode - it counts all metal fine.
But when I set 'Look in stockpile zone N' - it always shows zero count despite that there's lots of metal there.

[fritzgryphon]

Stockpile zone 1 has only finished steel.  The smelter will smelt steel slag chunks, like the ones by the helmet and medicine.

edit:  It is misleading how the resource drop down on the top-left shows steel underneath a slag chunk heading.

[LWM]

Steel is the finished product for slag smelting?

[fritzgryphon]

You got it.  Slag chunks are usually found as the debris from destroyed buildings or ships.  You can smelt the chunks back into usable steel.

[Canute]

I can confirm this.
New test game, only 1 stockpile at the whole map, contain sone steel.
I even drop a metal slag at that stockpile.
But the bill only show 0 once i select that stockpile.