Anti theft false alarm

Hi, I was watching YouTube on my phone and suddenly the anti theft app locked my phone, loudly blaring “this phone has been lost or stolen.” I entered the correct pin and the screen froze but alarm still was going off. I went downstairs to grab my computer and came back to find the phone in working order. What was the cause of This? I would hate for it to happen again like that. Any help is appreciated.

My Avast anti-theft triggered in the middle of a phone call. Entering the correct pin did not work, it’s stuck in a continuous loop. Can anyone help with this, please!