Hi @Marco_Giovanazzi, welcome to Zwift forums! Trainer calibration over Bluetooth was temporarily removed in our update in late February so that we could work to iron out some kinks in the system. We will be adding it back in with a future update, but in the meantime, you can calibrate the trainer in Elite’s My E-Training app. Once finished, the calibration will save to the trainer, and carry over to Zwift. 
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