Bug Description:

The metal (steel and aluminium) immersive engineering scaffolding do not have a recipe in the JEI, but they still craft with the same recipe as the treated wood ones, when steel scaffolding is selected only the two slab recipe and the shapeless recipe is shown alongside the chisel recipes.

Did this behavior use to work in the previous version?

No idea

Steps to Reproduce (for bugs)

1. Open JEI
2. Search for scaffolding
3. Right click scaffolding

Logs

N/A not a crash

Client Information

• Modpack Version: 3.17
• Java Version: Native launcher
• Launcher Used: Curseforge 0.166.1.4
• Memory Allocated: 4Gb
• Server/LAN/Single Player: Single
• Optifine Installed: NO
• Shaders Enabled: NONE

World Information

• Modpack Version world created in:
• Additional Content Installed:

Experienced this myself but I, as well as you, might have missed something.
Can't reproduce in the world I am in now as I am Age V.

It's because there are 3 versions of that item. JEI I think only shows one? If more than one, click another. I see 3 in Age V.
Try left-clicking the scaffolding to scaffolding recipe (left side). It should show you the source block.
Otherwise, make sure you aren't missing the third recipe on page 2 (don't ask why it's at the end not the start of suggested recipes). It used to hide there for me but now it doesn't. Might be because of Age V or because I changed my UI size to Large (Auto was slightly bigger and fit less on the screen).