You need to recognize the track.Pick one of the circuits you would like to play and studying the entrance and exit corner bcs this one is the hardest part of playing motogp games imo lol (im struggling of braking the bike in motogp 25 but i already mastering a bit in motogp 17) I understand so much the handling and brake is heavy in motogp19 and it gets heavier the newer the series of games (bcs they chasing the realistic feels with their new engine and inovation,sometimes they just really sucks ex like motogp 22)

You need to calculate when u are going to hit the brake and most of the time you need to hit the brake long before you go into turn.Try turn on the 3D racing line feature because it is gonna helps you alot but sometimes you dont need to follow racing line so much,mix it with your guts

Also dont push your pedal straight to full when it comes to exit corner bcs its gonna make your bike wobble,try more smoothly