Issue: ESC turns on max after a while of using

Hello. I have Sunnysky X2212-13 980KV Brushless Motor & SimonK 30A ESC. I have calibrated them successfully but after a while of using (about 30 seconds from start), ESC beeps and motor goes on maximal power. I can’t stop it with PWM on ESC input. The only possibility to stop it is disconnect the battery. What should I do to solve this issue?