Power increase in "out of the saddle" position

[livestrong13]

Hello,

I have the Ibike Newton power meter since 6 months and i'm very happy with it.

However, i have noticed a "strange" power readings behavior when i'm in the "out of the saddle" position. For the same speed and pace, the Newton displays 50 Watts higher in average than the sitting position.
I'm a climber, and i used to train in the mountains with long climbing sections. And so it's important for me to alternate the two positions.

Why the Watts are higher in "out of the saddle" position? It is normal or is there a logical explanation?

Thanks in advance.

[Velocomp]

Please post a ride file and we will take a look.

[livestrong13]

Here is in attachments, 2 examples of short rides.
Each time i was "out of saddle" (Isaac software is very good and detect it) we see a peak of the power and it is clearly higher during the time i stay in this position, in comparison with the sitting position.

Thanks in advance for you feedback!