CraftSim thinks I have 5 Arathor's Spear herb to craft this item for a patron order, but I do not. The reagent is not being supplied by the NPC either. Any additional information I can provide to help troubleshoot this?

I do have some of the herb in my warband bank, so maybe it's pulling from there? Currently we cannot complete crafting orders using reagents from warband bank but that will change in 11.0.5.

its looking at ur warbank which is intended
this will be working when blizz fixes their bug

make sense,. thank you!