Sounds to me like you probably don't have as good of communication as you think you do. Have you ever flat out asked her if she enjoys it or not? If she said no try to figure out ways together that can make it work for both of you. Maybe she's just as confused as you are
You didn't say, but does she EVER give you oral? If so, try to remember the event's that lead up to it and try to recreate it

b