autobloquearse

To block oneself — a device or account locking itself out (el teléfono se autobloquea tras varios intentos fallidos), or, figuratively, a person freezing up or getting in their own way emotionally or mentally.

• El teléfono se autobloquea después de cinco intentos fallidos. — The phone locks itself after five failed attempts.
• Se autobloqueó ante el examen y no pudo escribir nada. — He froze up in front of the exam and couldn't write anything.
• La app se autobloquea si detecta actividad sospechosa. — The app locks itself if it detects suspicious activity.

Assuming autobloquearse always refers to technology — the figurative sense (a person mentally freezing up under pressure) is just as common in everyday speech.