I don't think anybody have touched upon this yet but... have you made sure your gear is updated? I remember the starting quest only gives you the left side of the gears & none from the right side.
Another thing to keep in mind was how janky trying to target NPCs in duties. It might be wise of you to have the NPC on your focus target so you can easily switch targets. AoE heals do hit NPCs in more recent expac duties but synced at lv70 you're going to have to ST heal that NPC more often if you're having any difficulty with that.
