Aircrafts pitch up by itself

I was taking off today with a 777, and randomly it starting pitching upwards at 100kts ground speed. Then I tried with a 737, then with a few other aircrafts. As soon as it takes off by itself, the plane stalls. This never happened before. Any problem?

Are you calibrating the plane too high? Any excessive trim?

Okay I fixed it. Seems to have been a calibration issue. All good now. Thanks!