Calibration offset

Every once in while when I calibrate I get something like this in the picture. Whenever it calibrates this way it seems a little off, like more resistance than usual judging by my HR. I use a Vortex smart trainer and calibrate through the Tacx utility app first. Then I close out the Tacx app and calibrate through my TR workout. No separate power meter and I use Ergmode. PSI is always at 120 which is what Tacx suggests. Thanks in advance.