Hi! I'm going to reference the issue I made here: Shadows-of-Fire/FastWorkbench#44

I hope you will forgive me copying and pasting what I wrote there, instead of using the template:

Hello! I'm using FastWorkbench 3.1.1 and Polymorph 0.6 on Forge 31.2.31, and I'm having an issue where recipes other than the primary one don't seem to be selectable. The Polymorph icon is visible, both recipes show up in the GUI, but regardless of which one is clicked on, the output slot only ever shows the first option.

Disabling FastWorkbench allows the selection to function as intended, so I believe it is a conflict with just these two mods.

Let me know if I can get you any other information! Thanks very much!