Pixhawk 4 mini flight test unstable

ello today i did my first test fly it when crazy unstable and land down hard …few times i did the fly test and it same …when it took off from ground started to going crazy flying up down left right by it self …
The installation is with quadcopter x and gps is place beside the fc pixhawk 4 mini …is this ok or im wrong for this installation ???
The calibration and the flight controller orientation of yaw= 270* is prefect no error and problem …remote controller radiomaster TX16S and receiver frsky RX8R pro Need some help here …tqvm
Flight Review (px4.io)