SkySafari 6-pro will not perform a calibration after initial alignment. Also it will not add additional alignment points. I receive an "Operation Failed" error relating to the StarSense Autoalign accessory. The messages typically state something related to a pointing error or too few stars. Note I had this same issue with SkySafari 5-pro.
The issue is consistent between my Celestron Evolution mount and my Celestron Advanced VX mount with the SkyPortal Wi-Fi module. I do not use a hand controller with either mount.
The Celestron SkyPortal App for IOS does not exhibit these symptoms. And works flawlessly in alignment and calibration.