I have noticed this several times now whenever building a Monk character using the charactermancer-- when taking the Class Equipment option, once the character is finished being built and changes are applied, the Darts appear in the Equipment section but not in the Attacks & Spellcasting section. You basically have to delete the Darts in the Equipment, do a search for Dart in the compendium and re-add them to the sheet in order for it to properly populate them as an Attack.