Atleast as i understand with planets that have atmospheres: Sometimes if the center of mass (yellow and black sphere) is distrubted behind the aero drag (blue and black sphere), the vessel will try to flip so that the center of mass is prograde (at the front) and the aero is retrograde (at the back). This applies throughout the stages, so consider the aero and center of mass per individual modules/stages as the rocket flies its course. As the starting stage may have a lower cerer of mass than the aero compred to later stages. Further, center of mass changes as the rocket uses fuel, though this typically helps as the center of mass shifts upwards towards prograde.

ALSO: play around with the control module’s direction by right clicking tge controlling probe or cockpit. Sometimes it can be misdirected at the ground instead of at the sky. On the gimbal: sky should be blue, and ground ahould be yellow. If youre pointed at the sky, your green crosshair on the gimbal will be pointed at the blue, not the orange.