Signals Notebook: Reactant details in Stoichiometry table go missing after moving a reagent slightly above or below in the reaction field

This is a known limitation.

Workaround:

This happens when adding reagents using ChemDraw toolbar, however the same is not reproducible when the reagents are added using QuickAdd because using QuickAdd introduces the Plus Symbol between reagents and this makes the reagent being recognized as part of the reaction