Yeah, this one's common. You're likely bumping the brake handle forward with your left hand during use. It's a safety feature, but it's sensitive.
The chain kickback brake handle has two positions: all the way back toward you is run, all the way forward away from you is brake. If your wrist or palm hits it during a cut, it'll snap forward and stop the chain instantly.
Focus on your grip. Your left hand should be on the front handle with your thumb wrapped underneath it. This keeps your palm lower and away from the brake handle's lever. It's a more controlled stance anyway—your left arm should be straight with the elbow locked to help withstand kickback forces.
IF THAT DIDN'T WORK: There's a small chance the brake mechanism itself is defective or has debris in it. With the battery removed, work the handle back and forth. It should move smoothly. If it's sticky or gritty, it might need service.
HEADS UP: Don't disable or modify the brake. That handle is there to stop the chain if the saw kicks back toward you. It's annoying when it trips, but it's literally a safety brake.