Correspondence between real and simulated gradient

[liber63]

Hello.
I have recently bought a Direto XR and I am testing its capabilities, and obviously, learning how to best use it.

Today I tested a Map course along a climb I know very well, so that I could make a reasonable comparison.

I prepared the KML with Google Maps and the itinerary seemed to me correct and smooth, and so it did behave during the ride.

My only problem is that during some inclines I found they were much harder to negotiate than the real ones.
The grades displayed on the screen seemed reasonable to me, respect to the real ones (starting from 4% and peaking at 9-11%).
I know even the smallest potholes of this road, so I know what I am saying. I know how I feel on this road in every physical condition and at the moment I am still in good shape, though Winter is going to take its toll.

I used the 100% setting, since my intention was not to "cheat" and make the ride easier than it should be. I know Zwift (not tried yet) by default starts at 50% and I did not want to feel stronger than I am.
But in the end I had to to decrease the percentage to 85% to make it feel about the same I feel while doing the "real" thing.

Of course, I have carried out power calibration beforehand.

I still only tried the Android app, since I am waiting the ANT+ sensor and my PC cannot connect to the Direto by Bluetooth (I tried everything and checked compatibility).

I am missing something (probably stupid)?

Thank you for any advice!

Liber